CHAPTER 19 Infectious diseases 702 Prolonged fever of unknown cause A fever without apparent cause that has persisted for >21 days is de \201 ned as \200\230prolonged fever of unknown cause \200\231. An explanation is found eventu- ally in the majority of cases. One-third of these will be infectious, and the remaining due to other causes, e.g.: \200 Rheumatological: eythematosus, rheumatic fever, vasculitis (see b pp.244, 768 \200\223776, 780, 788 \200\223791); periodic fever syndromes. juvenile rheumatoid arthritis, systemic lupus IBD \200 \200 \200 \200 (b p.332). (b p.661). Malignancy Drug fever . Factitious illness (b p.999). Examination and assessment A thorough history and examination are required. Also consider o ther fac- tors such as travel, geography, age, and signi \201 cant exposures. Appropriate investigations include: \200 \200 \200 Blood: Serology: Culture: stool culture, and consider need for lumbar puncture and bone mar row culture. Imaging: Bone Echocardiography: Skin and blood tests: FBC, CRP, ESR, LFTs and renal function tests, albumin. CMV, EBV, brucella, and Q fever. at least 3 serial adequate volume blood cultures, urine cu lture, \200 \200 \200 of sinuses in the older child and CXR. scan or MRI: to exclude osteomyelitis. to exclude endocarditis. for TB and blood test for HIV after counseling. Treatment \200 Antibiotics: found. However, in many cases they will have been prescribed already. Remember that antibiotics may be the drug agent causing fever. If the child is cri tically ill then empiric antibiotics are given. Antipyretics: these are best avoided during the period of assessment of fever. For example, blood cultures should be taken when the pa tient is febrile. One can also determine whether there is a speci \201 c pattern to the fe ver. these are best avoided until a site of infection has been 19_McClure_19.indd 702 11/14/2012 3:51:53 PM PROLONGED FEVER OF UNKNOWN CAUSE 703 19_McClure_19.indd 703 11/14/2012 3:51:53 PM CHAPTER 19 Infectious diseases 704 Common infections characterized by rash Infections in childhood often have an associated ra sh. The skin lesion will give some clue to the potential cause (Box 19.6). Box 19.6 Skin lesions associated with infection See b p.806 for de \201 nitions. \200 Ma cules and/or papules: \200 Macules \200\224 \200 Papules \200\224 Infections \200\224 P urpura and/or petechiae: on pressure. Infections \200\224meningococcal, enterovirus, Haemop hilus in \202 uenza, pneumococcal Vesicles: small raised lesions that contain clear \202 uid. Infections \200\224 chickenpox, shingles, herpes simplex virus, and hand, foot, and m outh disease Bullae and pustules: Infections \200\224staphylococcal/streptococcal impetigo and scalded skin Desquamation: peeling skin, often of the hands and feet. Infections \200 \224 Kawasaki \200\231s disease and after scarlet fever (post-streptococcal infection) red or pink discrete, \202 at areas that blanch on pressure small, raised lesions that bl anch on pressure measles, rubella, human herpes virus 6, and enterovirus \200 red or purple spots that do not blanch large raised lesions containing clear \202 uid or pus. An exanthem is a rash that \200\230bursts forth or blooms \200\231 towards the end of incubating an infection. The six classic exanthemata are characteristically: \200 \200 widespread, symmetrically distributed on the body; red, discrete, or con \202 uent macules or papules. Box 19.7 gives a summary of the exanthemata. Look at the following sec- tions for more deta ils. 19_McClure_19.indd 704 11/14/2012 3:51:53 PM COMMON INFECTIONS CHARACTERIZED BY RASH 705 Box 19.7 The six exanthemata First associated disease: measles virus \200 8 \200\22312 days \200 \200 \200 \200 Incubation: Duration: Infectivity: Rash: Features: spots on the oral mucosa rarely seen Tre atment: 6 \200\2238 days from 4 days before to 4 days after the rash appears maculopapular; starts on the face and spreads prodromal upper respiratory symptoms and cough, Koplik supportive, contact public health Second associated disease: group A streptococcus \200 \200 \200 \200 \200 \200 Incubation: Duration: Infectivity: Rash: Features: Treatment: where infant less than 1mth o f age or multiple family members affected 2 \200\2235 days 7 days can become colonized \201 ne papular rash on \202 ushed skin, sandpaper texture sore throat, strawberry tongue, rash, lymphadenopathy penicillin V, consider need for prophylaxis only in family Third associated disease: rubella \200 \200 \200 \200 \200 \200 14 \200\22321 days Incubation: Duration: Infectivity: Rash: Features: Treatment: 2 \200\2233 days from 7 days before to 7 days after the rash maculopapular, rapidly spreads and fades enlarged lymph nodes at the back of the neck and ears supportive Fourth associated disease: possible coxsackie virus No longer recognized as a disease entit y Fifth associated disease: parvovirus \200 4 \200\22314 days \200 Incubation: Duration: evanescent rash over 1 \200\2233wks followed by arthropathy Infectivi ty: Rash: Treatment: 3 \200\2237 days prodrome then rash for 1 \200\2234 days; then \200 \200 no isolation needed for children slapped cheek appearance, erythema infectiosum supportive Sixth associated disease: human herpes virus 6 \200 \200 \200 \200 \200 Incubation: Duration: Infectivity: Rash: Features: temperature falls rapidly Treatment: 10 days 3 \200\2237 days unclear maculopapular temperature for 3 days then, as the rash appears, the supportive 19_McClure_19.indd 705 11/14/2012 3:51:53 PM CHAPTER 19 Infectious diseases 706 Exanthem 1: measles Measles occurs typically in preschool and young children with the peak incidence in late winter and spring. Signs and symptoms \200 the p infection occurs in the respiratory epithelium of the Prodrome: nasopharynx, and produces fever, coryza, cough, and non-purulent conjunctivitis. Occasionally, a characteristic sign in the mouth is seen opposite the low premolars \200 \224 \200\230Koplik spots \200\231 (which look like grains of sugar on the mucosa). After 2 \200\2233 days there is a viraemia with infection of the reticuloendothelial system. Exant hematous phase: initial infection with rash developing some 14 days after initial infection . The maculopapular rash starts on the face and lasts 6 \200\2238 days. Infectivity: Other features: fever (may persist 7 \200\22310 days). Incubation 7 \200\22318 days (av. 10 \200 \2232 days). a second viraemia occurs 5 \200\2237 days after the \200 4 days before to 4 days after the onset of rash. generalized lymphadenopathy, anorexia, diarrhea, and Diagnosis \200 Clinical: \200 Blood \201 lm: \200 LFTs: \200 Oral \202 uid test : diagnosis. Serum serology may also be used. Koplik spots are pathognomonic, but usually seen. leucopenia and lymphopenia. raised transaminases. measles RNA on oral \202 uid specimen con \201 rms the Management \200 Acute treatment: generally supportive, but could include antibiotics for secondary bacteria l infection (e.g. pneumonia, otitis media, tracheitis). Individuals are highly contagious d uring the viraemia. Prevention: children. Vitamin A: malnutrition lead to a protracted cour se of illness with severe complications. The rash is dark red and is followed by desquamati on and depigmentation. Consider supplements in children older than 6mths. MMR vaccine at 12 \200\22318mths and preschool booster to all in developing countries vitamin A de \201 ciency and Complications Complications commonly occur in young children with almost 20% of cases havin g at least one additional problem. \200 \200 otitis media (10%). respiratory tract infection (LRTI; 5%): bacterial pneumonia, Acute Lower interstitial pneumonia, bronchiolitis, laryngotracheobronchitis. Encephalitis a nd starts with headache, lethargy, irritability, followed by seizures and coma. Mortality i s high and there are neurological sequelae in survivors. Subacute sclerosing panencephaliti s neurological disease with progressive intellectual deterioration, ataxia, and seizures ab out 7yrs after measles infection. (1 in 5000): occurs 78 days after the onset of illness (SSPE, 1/10 000). A rare and fatal 19_McClure_19.indd 706 11/14/2012 3:51:53 PM EXANTHEM 2: GROUP A STREPTOCOCCUS 707 Exanthem 2: group A streptococcus Scarlet fever is an erythematous rash that may occur with streptococcal pharyngitis. Other patterns of infection caused by group A streptococcus inc lude toxic shock syndrome and necrotizing fasciitis. Signs and symptoms \200 infection is spread by respiratory secretions and droplets, or Prodrome: by self-infection from nasal carriage. During the incubation period (2 \200\2235 days) the child may have fev er, vomiting, and abdominal pain. Exanthematous phase: chest area (with perioral pallor) sp reading to the \202 exor creases. The pharynx is erythematous and there may be exudative tonsillitis, palatal petechiae, uvular oedema, and strawberry tongue. Other features: \200\230sandpaper-like \200\231 diffuse rash in the neck and tender anterior cervical lymphadenopathy. Diagnosis \200 Throat swab: individual (note also asymptomatic carriage common) Serum: both may rise in ac ute infection. culture and growth of the organism in a symptomatic antistreptolysin O (ASO) and anti-DNase B titres \200\223 one or Management \200 Antibiotics: penicillin V for 10 days. This will prevent the development of rheumatic fever (but not glomerulonephritis) and may reduce the length of illness. Antib iotics should be started within 9 days of acute illness. Isolation: antibiotics. children should be isolated until 24hr after the start of Complications Include peritonsillar abscess, retropharyngeal abscess, acute glomeulone- phr itis, and rheumatic fever. 19_McClure_19.indd 707 11/14/2012 3:51:53 PM CHAPTER 19 Infectious diseases 708 Exanthem 3: rubella Rubella is a mild disease in childhood occurring in winter and spring. Signs and symptoms \200 Prodrome: child may have a mild illness with low-grade fever. Exanthematous phase: spreadin g to cover the whole body, and lasting up to 5 days. Other features: the incubation period is 14 \200\22321 days during which time the maculopapular rash starting on the face, then suboccipital and post-auricular lymphadenopathy. Diagnosis Serology If there is a risk of a non-immune pregnant woman has been exposed to th e child, then the diagnosis should be con \201 rmed by serology. Management \200 Supportive. \200 Prevention: immunization with MMR (see b p.728). Complications Very rarely children may develop arthritis, myocarditis, encephalitis, or thr ombocytopenia. (When MMR vaccine uptake is reduced, remember fetal rubella syndrome if a no n-immune mother is infected early in preg- nancy.) Exanthem 4: enteroviruses The majority of infections due to human enteroviruses (coxsackie viruses, echoviruses, and polio viruses) produce non-speci \201 c illness. They occur in t he summer and autumn months, and occasionally there are characteristic features including t he following: \200 Meningoencephalitis: which can present like meningococcal septicaemia (see b p.714). Pleuro dynia: muscles Myocarditis Hand mouth, and tongue. Herpangina: uvula. Polio: immunizatio n. aseptic meningitis with an associated skin rash, febrile illness with pleuritic chest pain and tender thoracic \200 , foot, and mouth disease: painful vesicles on the hands, feet, vesicular and ulcerated lesions on the soft palate and this condition should be eradicated with effective global 19_McClure_19.indd 708 11/14/2012 3:51:53 PM EXANTHEM 5 AND 6 709 Exanthem 5: parvovirus Parvovirus B19 induces immune complex formations that deposit in joi nts and the skin, causing \200\230erythema infectiosum \200\231. It also infects the eryth roblas- toid precursors in the bone marrow. The infection occurs in all ages and is more co mmon in the winter and spring. Signs and symptoms \200 Prodrome: infection spread by respiratory secretions and droplets. Then low-grade fever, he adache, and coryza 7 days after exposure. Exanthematous phase: a number of days; bright red macules on the face with a \200\230slapped-cheek \200\231 appearance, (also, peri-oral pa llor). The rash spreads to the limbs sparing the palms and soles. It is more intense with e xposure to sunlight, heat, exercise, and stress. Other aplastic crisis, fetal hydrops (from maternal infection). features: other patterns of illness include asymptomatic infection, Diagnosis \200 Clinical: \200 Serology: characteristic rash. if the diagnosis is in question titres can be measured. Management is supportive: antipyretics for fever. Exanthem 6: human herpes virus 6 Human herpes virus 6 (HHV6) is a benign, self-limiting exa nthem com- monly infecting children by the age of 2yrs. It is also known as \200\230roseol a infantum \200\231 and \200\230erythema subitum \200\231. Signs and symptoms \200 . High-spiking fever up to 41*C lasting for up to 4 days. The Prodrome fever typically stops once the rash appears. Exanthematous phase: the rose-colored maculopapular rash appears some days later, beginning on the trunk and spreading periphera lly. It lasts for 2 \200\2235 days. Other features: vomiting, diarrhea, pharyngeal injectio n without exudates, cervical lymphadenopathy, and febrile convulsions prior to rash (5 \200 \22310% of cases). Diagnosis is on clinical grounds. Typical history and there may be associ- ated neutropenia . Management is supportive: antipyretics for fever. Complications The most common complication is febrile convulsion, and HHV6 probably account s for a third of these in those <1yr of age. Rarely, some children may develop aseptic meni ngitis, encephalitis, and hepatitis. 19_McClure_19.indd 709 11/14/2012 3:51:53 PM CHAPTER 19 Infectious diseases 710 Rash: chickenpox and zoster VZV infection typically occurs between the ages of 1 and 6yrs, with the maximal transmission during winter and spring (b p.827). Signs and symptoms \200 Prodrome: VZV is spread by respiratory droplets or direct contact with lesions. The infecti ous period begins 2 days before vesicles appear and ends when the last vesicle crusts over (it is possible to retrieve virus from a crust). Rash: usually starts on the head and trunk ; then the rest of the body. Individual lesions start as red macules, then progress through stages: papule, vesicle, pustule, crusting. Different stages of the rash are seen at the s ame time and heal completely within 2wks. Other infection (i.e. sore throat, cough coryza), fever, and itching. features. Headache, anorexia, signs of upper respiratory tract Diagnosis \200 Clinical \200 Other . Characteristic rash, its distribution, and progression Serology (VZV IgM), electron mi croscopy of vesicle \202 uid. Management \200 Symptoms: \200 School exclusion: \200 Antivirals: aciclovir is used i n severe varicella, encephalitis, pneumonia, babies, and immunosuppressed patients (i.e. st eroids, oncology, etc.). VZIG: Varicella zoster immunoglobulin should also be considered as prophylaxis following contact in at risk individual (see www.hpa.org.uk for guidance). Imm unization: treatment of fever and itching. 5 days from start of skin eruption from age 1 not currently part of UK schedule Complications s bacterial infection may occur with invasive group A streptococcus lead- ing to necrotizing fasciitis or toxic shock syndrome. Other rare complica- tions include purpu ra fulminans, cerebrovascular stroke, and encephalitis. Life-threatening pneumonitis may oc cur in the young infant and immuno- suppressed child. Herpes zoster (shingles) A reactivation of latent infection may occur, leading to vesicular lesions in the distribution of a sensory nerve. Rare in childhood, but occurs in the immun osuppressed, or in those who had p infection in infancy. 19_McClure_19.indd 710 11/14/2012 3:51:53 PM RASH: INFECTIOUS MONONUCLEOSIS 711 Rash: infectious mononucleosis Infectious mononucleosis is caused by EBV (90%) and CMV. The source is oropharyngeal secretion. Virus infects B lymphocytes in pharyngeal lym- phoid ti ssue and then spreads to the rest of the lymphoid system. Signs and symptoms \200 Prodrome: days. The incubation period is 4 \200\2236wks. Features: hepatosplenomegaly; wide spread erythematous macular rash, especially if inadvertently treated with ampicillin; leth argy. \202 u-like illness (headache, low-grade fever, and chills) for 3 \200\2235 exudative pharyngitis; generalized, tender lymphadenopathy; Diagnosis triad: lymphocytosis (80 \200\22390% of WBC); (cid:2)10% atypical \200 Classic lymphocytes on peripheral blood \201 lm; positive serology for EBV. Monospot lymphoma and hepatitis. Other. IgM and IgG are raised early in the disease; raised liver function tests ; mild thrombocytopenia. Quantitative PCR in immunosuppressed (not for routine diagnosis). test: a low-sensitivity test with false positives occurring in Management \200 Symptoms: \200 Splenomegaly: for 1mth, and adolescents should avoid alc ohol. supportive care patients with splenomegaly should avoid contact sports Complications \200 \200 \200 \200 GI CNS: Post viral tiredness: Other. and abdominal: hepatitis, splenomegaly, and splenic rupture. aseptic meningitis, encephalit is, Guillain \200\223Barr syndrome. is self-limiting, but may take months to resolve. lymphoma, orchitis, myocarditis, pneumonia. 19_McClure_19.indd 711 11/14/2012 3:51:54 PM CHAPTER 19 Infectious diseases 712 Lyme disease \200 \200 \200 \200 Cause: Age Incubation: Rash: and forms a painless red lesion called erythema migrans. Early arthralgia, and lymphadenopathy \202 uctuate over several weeks. Later time course (mont hs): nerve palsies, meningitis, arthritis, or myocarditis. Diagnosis: Treatment: >8yrs use doxycycline. In those with heart or CNS disease use ceftriaxone. spirochaete Borrelia burgdorferi transmitted by tick bite. group: any age. 4 \200\22320 days. erythematous macule at the site of the tick bite increases in size time course (weeks): the symptoms of fever, headache, myalgia, dissemination of infection leads to cranial \200 the clinical features and serology after 2 \200\2234wks. in the young child amoxicillin is used. In the child aged 19_McClure_19.indd 712 11/14/2012 3:51:54 PM MUMPS 713 Mumps Mumps is a viral infection transmitted by respiratory droplets. The virus enters the parotid gland before systemic spread. The peak incidence is in children aged 5 \200\2239yrs . Signs and symptoms \200 Prodrome: incubation period is 14 \200\22321 days. Features: is parotitis. In these patient s there is often ear pain and tenderness over the gland. Other cough, and coryza), and low- grade fever. myalgia, anorexia, headache, low-grade fever, and chills. The 20% of infections are asymptomatic. In 30 \200\22340% of cases there features: headache, anorexia, signs of URTI (i.e. sore throat, Diagnosis \200 characteristic examination with glandular swelling. Clinical: \200 Other . salivary PCR or serology (mumps IgM) in the \201 rst week of illness; delayed viral cul ture of saliva or urine; blood shows lymphocytosis and increased amylase. Management \200 Symptoms: \200 Immunization: supportive care. MMR vaccine confers lifelong immunity. Complications \200 Meningoencephalitis: asymptomatic. Orchitis: (see b p.877). Other: the most common complication and it is usually results in testicular swelling, local pain, and later atrophy oophoritis, pancreatitis, and myocarditis. 19_McClure_19.indd 713 11/14/2012 3:51:54 PM CHAPTER 19 Infectious diseases 714 Bacteraemia and shock Bacterial infection leading to \200\230sepsis syndrome \200\231, and shock is discussed in b Chapter 5 (b pp.54, 56 \200\22357, 70, 90). The most common cause of bacteraemic shock is Neisseria meningitidis, although Staphylococcus aureus is in increa sing as overall proportion and Streptococcus pneumoniae re- mains an important cause even i n the era of routine infant 13 valent con- jugate pneumococcal immunization. Meningococcal septicaemia and shock Meningococcal disease is rare, but it can be fatal in a previously well child. Unfortunately, at an early stage, the signs and symptoms are non-sp eci \201 c and the child may have features similar to those of a minor viral illness. Meni ngococcal disease has therefore featured highly in public educa- tion; the \200\230glass t est \200\231 is used to identify a typical non-blanching purpuric or petechial rash. Pathogenesis In the UK, N. meningitides serogroup B is the usual cause of illness. (sero- g roup C is rare since its inclusion in routine vaccination). The trigger and mechanism of in vasion are unknown. Once bacteraemia occurs, bacterial autolysis leads to endotoxin release and systemic illness with disseminated intravascular coagulation, capillary leak, and dist ributive and cardiogenic shock. Signs and symptoms \200 Non-speci \201 c: followed by poor urine output. Pain in proximal muscles, joints, and abd omen is very common. initially maculopapular, then petechial or purpuric. Rash: CNS: associ ated meningitis in 20 \200\22330%. Altered conscious level may be due to shock rather than meningitis and respond to initial \202 uid therapy. Raised ICP is more common in meningit is presentation (e.g. headache, neck pain or stiffness, irritability, and altered conscious level) than sepsis. Respiratory: following initial \202 uid therapy fever, malaise, thirst may be the \201 rst sign of shock, \200 features of pneumonia or pulmonary oedema, especially Diagnosis Any febrile child who develops a purpuric rash should be considered to have menin gococcal septicaemia until proven otherwise. Management See b Chapter 5 (b p.54). Suspected cases in the community should receive IV ben zylpenicillin (IM if no IV access) as an initial single dose: \200 \200 \200 (cid:2)10yrs, 1g. Children 1 \200\2239yr olds, 600mg. <1yr, 300mg. Suspected cases in hospital should receive 80mg/kg/od ceftriaxone (or cefotaxime 50mg/kg/td s. In shock, 20mL/kg \202 uid volume should be given immediately, consideration given to repeat \202 uid boluses followed by 19_McClure_19.indd 714 11/14/2012 3:51:54 PM BACTERAEMIA AND SHOCK 715 intubation and ventilation and inotropes following early consultation with pediatric intens ive care. Careful attention should be made to correc- tion of electrolyte imbalance, partic ularly potassium (which is low even in anuric renal failure due to meningoccaemia) and calc ium. A management algorithm for health professionals based on the NICE clinical guideline 1 02 is available at M www.nice.org.uk/CG102. Complications The majority of survivors of meni ngococcal disease have few or no se- quelae. However, there is a signi \201 cant mortality (2 \200\2234%), and morbidity includes loss of digits and limbs due to peripheral vascular disease. 19_McClure_19.indd 715 11/14/2012 3:51:54 PM CHAPTER 19 Infectious diseases 716 Kawasaki disease Kawasaki disease is the commonest cause of acquired heart disease in child ren in the UK. It affects 3.4/100,000 children under 5yrs (boys > girls) and in the UK mort ality is 3.7%. It is a systemic vasculitic disease with coro- nary arteritis leading to cor onary artery aneurysms as the most important complication (20 \200\22330%). Other complicat ions include coronary thrombo- sis, myocardial infarction, and dysrrhythmias. Diagnostic criteria The diagnosis can be made in children with fever (>38.5*C) present for at least 5 days, without other explanation, in the presence of 4 of the 5 following criteri a. Criteria may not be present at the same time (history is important) and misery is a very common feature. \200 \200 Bilateral Changes dryness, erythema, \201 ssuring of lips (70%); strawberry tongue (71%); diffuse erythema of oral and pharyngeal mucosa without discrete lesions (70%). Changes of palms and soles (80%); indurative oedema (67%); periungual desquamation of \201 ngers and toes (29%). Polymorphous exanthem (92%). Non-suppurative cervical lymphadenopathy >1.5cm ( 42%). congestion of the ocular conjunctivae (94%): non-purulent. of the lips and oral cavity with at least one of the following: of the extremities with at least one of the following: erythema \200 Note: The percentage values indicate the proportion of patients manifest- ing this clinical sign within the \201 rst 10 days after onset of fever. Differential diagnosis The differential diagnosis for Kawasaki disease includes the following: \200 \200 \200 \200 \200 \200 \200 IBD \200 \200 Streptococcal and staphylococcal toxin-mediated diseases Adenovirus and other viral infecti ons (enterovirus, measles) Drug reactions or Stevens \200\223Johnson syndrome Leptospirosis Yersinia Rickettsial infection Reiter \200\231s syndrome pseudotuberculosis infection Post-infectious immune complex disease (e.g. post- meningococcaemia) Sarcoidosis Associated features In addition to the diagnostic criteria of Kawasaki disease, the other f ea- tures of the condition include the following. \200 urethritis with sterile pyuria. \200 Renal: Musculoskeletal: arthralgia and arthritis (35% of patients). 19_McClure_19.indd 716 11/14/2012 3:51:54 PM KAWASAKI DISEASE 717 CNS: glucose and protein; sensorineural hearing loss (transient high frequency loss or perm anent loss). GI: obstructive jaundice. Cardiac: arrhythmias, mitral insuf \201 ciency, acu te myocardial infarction (up to 73%) within 1yr of disease. Coronary (15 \200\22325% in unt reated patients) and resolution varies with age at onset and size and shape of aneurysm. aseptic meningitis with mild CSF pleocytosis and normal CSF diarrhea and vomiting; hydrops of the gall bladder with or without congestive heart failure, myocarditis, pericardial effusion, aneurysms: incidence of coronary artery aneurysms varies Investigations \200 Hematology: thrombocytosis peaks in the 3rd to 4th week; normocytic, normochromic anemia present early and persists until in \202 ammatory process begins to su bside; reticulocyte count low. Coagulation: \201 brinolysis. Urine: the urine early in th e disease. These cells are not detected by dipstick methods for \200\230WBC \200\231, whic h only detect polymorphs. Acute phase reactants: elevated ESR persists beyond the acute feb rile period and gradually returns to normal over 1 \200\2232mths. CRP may also be elevated. Biochemistry: Immunology: B cell activation elevated immunoglobulin production; T cell lym phopenia. Cardiology: be present. Echocardiography: onset of fever. leucocytosis with left shift common in acute phase; increased coagulability, platelet turnover, and depleted mononuclear cells with cytoplasmic inclusions are abundant in \200 elevated liver transaminases; hypoalbuminaemia. marked activation of circulating monocyte/m acrophages; ECG usually normal, but strain, ischaemia, and/or infarct can aneurysms may \201 rst be seen from 7 \200\22321 days post- Treatment \200 High 12hr as a single infusion. Consider repeat dose after 48hr if no deferevescence. Aspir in: resolves. The role of steroids and novel biological therapies is not clear. Follow-up i s very important for cardiac review. dose IV immunoglobulin is the treatment of choice. 2g/kg over 30 \200\22450mg/kg/day (divided qds) reducing to 3 \200\2235mg/kg as fever \200 19_McClure_19.indd 717 11/14/2012 3:51:55 PM CHAPTER 19 Infectious diseases 718 Skin and soft tissues Impetigo \200 Cause: \200 Age \200 Features: erythematous macul es (later vesicular/bullous) on the face, neck and hands \200\224often associated with pre- existing skin lesions such as eczema. Infectivity: inoculation occurs and lesions are infec tious until dry. Antibiotics: topical antimicrobials are often not useful in younger childr en due to scratching causing further spread of bacteria; if treatment required, use oral an tibiotic, taking taste and formulation into account prior to prescription (oral \202 uclo xacillin and erythromycin are often poorly tolerated). staphylococcal or streptococcal skin infection. group: infants and young children. nasal carriage is often the source of infection. Auto- Boils (furuncles) \200 \200 \200 \200 Cause: Age Features: Infectivity: boils. Antibiotics: Staphylococcus aureus. group: any age. infection of hair follicles or sweat glands. nasal carriage is often the source of infectio n in recurrent systemic. Peri-orbital cellulitis See b p.919 \200 Cause: pneumoniae, rarely Haemophilus in \202 uenzae type b in unimmunized children. Age F eatures: the eyelid, often following local trauma to the skin. Complications include local abscess, meningitis, and cavernous sinus thrombosis. Investigations: if severe (eye movemen ts are not visible or complete ptosis) refer to ENT or ophthalmology and perform cranial CT scan. Antibiotics: IV ceftriaxone 80 mg/kg/od where eye movements are visible. Add IV metr onidazole if eye movements not visible or not improved at 24hr. group A streptococcus, Staphylococcus aureus, Streptococccus \200 group: any age. fever with unilateral erythema, tenderness, and oedema of Scalded skin syndrome \200 \200 \200 Cause: Age Features: around the eyes, nose, and mouth. Later diffuse erythema and skin tend erness leading to separation of the epidermis through the granular cell layer. Nikolsky \200\231s sign is epidermal separation on light pressure with no subsequent scarring after healing. Antibiotics: exfoliative staphylococcal toxin. group: infants and young children. fever and malaise with a purulent, crusting, localized infection IV \202 ucloxacillin 50mg/kg/qds. 19_McClure_19.indd 718 11/14/2012 3:51:55 PM SKIN AND SOFT TISSUES 719 Necrotizing fasciitis \200 \200 \200 Cause: Age Features: may be due to shock, systemic illness, and severe pain. Antibiotics: group A streptococcus, less commonly Staphylococcus aureus group: any age. SC infection of tissue down to fascia and muscle. Symptoms IV, and surgical debridement. Toxic shock syndrome (TSS) Cause \200 \200 Toxin-producing staphylococci or streptococci Multisystem disease due to staphylococcal tox in-1 in 75% Signs and symptoms \200 \200 \200 \200 \200 Systemic illness with high fever GI: vomiting, watery diarrhea Shock and hypotension, alter ed conscious level Neuromuscular: Skin rash: after infection desquamation of the palms, sol es, \201 ngers, and toes occasional severe myalgia red mucous membranes and diffuse macular rash; 10 days Investigations \200 \200 Hematology: Biochemistry: thrombocytopenia, coagulopathy abnormal liver and kidney function Diagnostic criteria for staphylococcal TSS (cid:2)39*C \200 Temperature \200 Systolic b lood pressure <90mmHg \200 Rash (may or may not include desquamation) \200 Involvement of three or more of gastrointestinal, musculoskeletal, renal, hepatic, CNS, blood, and muco us membranes Diagnostic criteria for streptococcal TSS \200 Isolation of group A streptococcus \200 Hypotension \200 Involvement of two or more of coagulopathy, adult respiratory distress s yndrome, soft tissue necrosis, rash with desquamation, or renal or hepatic involvement Treatment \200 \200 IV \202 uids and resuscitation Antibiotics against staphylococci and streptococci. Clinda mycin often added to \202 ucloxacillin regime due to anti-toxin activity in vitro IV immu noglobulin 19_McClure_19.indd 719 11/14/2012 3:51:55 PM CHAPTER 19 Infectious diseases 720 Meningitis 75% of cases of meningitis are believed to occur in those <15yrs of age. Three o rganisms (Streptococcus pneumoniae, Neisseria meningitides (mainly group B in the UK) and H aemophilus in \202 uenzae type b) account for 80% of the cases. H. in \202 uenzae and men ingococcal group C have declined very signi \201 cantly since the introduction of routine immunization in infancy. Three important practice points to remember are: Infants do not get classical symptoms of m eningism with meningitis and there should be an extremely low threshold for doing a lumbar puncture as part of the septic screen in infants with unexplained fever or seizures (see b pp.128, 180). Co-existing septicaemia in 20 \200\22330% is often the treatment priority to prevent death. Do not forget possibility of tuberculous meningitis. Pathogenesis The sequence of pathology involves: \200 \200 \200 \200 Colonization and invasion of the nasopharyngeal epithelium. Invasion of the blood stream. A ttachment to and invasion of the meninges. Induction of in \202 ammation with leak of prot eins leading to cerebral oedema. Alteration in cerebral blood \202 ow and metabolism. Cer ebral vasculitis. \200 Symptoms and signs In younger children symptoms may be non-speci \201 c including fever, p oor feeding, lethargy. Rash and seizures may or may not be present. In older children, feve r with headache and neck stiffness. Other features include: \200 \200 \200 General: Central: Seizures: subdural collection. Do not assume \200\230febrile convulsion \200\231 in child under 1yr of age or over 1yr of age with additional symptoms. Neck Neurol ogy: tuberculous or cryptococcal meningitis. Eyes: papilloedema is a late sign and not a re liable indicator of raised intracranial pressure. Retinal hemorrhages may be present and ma y indicate sagittal venous thrombosis or coagulopathy. However, these are rare and in the i nfant the possibility of non-accidental or in \202 icted head injury should be considered. fever, vomiting, and anorexia. irritability, disorientation, altered mental state. occur in 30%. Focal seizures suggest localized infarction or \200 stiffness: more common in older children. focal cranial nerve signs are more common in children with Lumbar puncture Lumbar puncture is a useful procedure to make the diagnosis of meningitis a nd identify the organism and it is generally safe. However, patients with bacterial meningi tis may have raised ICP so if there is a clinical suspicion of this problem (low heart rate with raised blood pressure, often \201 rst sign of which are transient changes seen on c ardiac monitors) then the procedure 19_McClure_19.indd 720 11/14/2012 3:51:56 PM MENINGITIS 721 should be deferred. (The cellular and chemical changes of meningitis will remain in the CSF for several days). The contraindications are: \200 \200 \200 \200 \200 \200 shock or cardiovascular instability; signs of raised intracranial pressure focal neurologic al signs or focal seizures infection of the skin at the lumbar puncture site (rare); eviden ce of coagulopathy; acute meningococcal disease Treatment See b Chapter 5 (b p.79). Suspected cases of meningococcal meningitis in the comm unity should receive IV benzylpenicillin (IM if no IV access) as an initial single dose. \200 \200 \200 (cid:2)10yrs, 1g. Children 1 \200\2239yr olds, 600mg. <1yr, 300mg. Suspected cases in hospital should receive 80mg/kg/od ceftriaxone (or cefotaxime 50mg/kg/td s). A management algorithm for health profession- als based on the NICE clinical guideline 102 is available at M www.nice. org.uk/CG102 Steroids In bacterial meningitis \200 \200 Do note use corticosteroids in children younger than 3mths There is bene \201 t from the u se of dexamethasone and the dosing schedule is 0.15mg/kg qds for 4 days to reduce the sever ity of neurological sequelae, particularly deafness, after bacterial meningitis (M www.nice .org.uk/CG102). If dexamethasone was not given before the \201 rst dose of antibiotics, b ut was indicated, try to give the \201 rst dose within 4hr of starting antibiotics, but d o not start dexamethasone more than 12 hours after starting antibiotics. In meningococcal septicemia \200 \200 Do not use the meningitic dosing of dexamethasone. In children with shock that is not respo nding to \202 uids and inotropes, physiological replacement of hydrocortisone (25mg/m2 qd s) should be considered after discussion with the intensive care team. 19_McClure_19.indd 721 11/14/2012 3:51:56 PM CHAPTER 19 Infectious diseases 722 Mycobacteria Pulmonary tuberculosis Pulmonary tuberculosis due to Mycobacterium tuberculosi s (an acid-fast ba- cillus) is discussed in b Chapter 9 (see b p.294). Atypical mycobacterial infection could be the cause of the following: Persistent a surgical ly resected node. Disseminated infection in the immunocompromised patient. Mycobacterium av ium intracellulare: is an infection often seen in patients with advanced disease due to HIV . lymphadenopathy: this infection is diagnosed after histology of Tuberculous meningitis (TBM) TBM is the most feared complication of M. tuberculosis infecti on. \200 usually occurs within 12mths of \201 rst infection. \200 group: most frequen tly occurs in those <5yrs of age. \200 Timing: Age Pathology: to the cerebral cortex from a p site (e.g. gut, lung). This increase s in size until it reaches the meninges and subarachnoid space. A thick gelatinous exudate is created especially around the brainstem so that cranial nerves III, IV, and VI are commo nly compromised. Hydrocephalus is common. Clinical course: the onset is insidious and is ch aracterized by apathy or disinterest, then intermittent headaches and anorexia. Fever is al most always present. Vomiting occurs in 50%. Focal neurological signs, seizures, or severel y depressed conscious level may occur. Diagnosis: or gamma interferon release assay often p ositive. 40 \200\22390% have CXR changes of pulmonary disease. Prognosis: most survive if t reated in the early insidious stage. There is a very high complication rate, especially if the focal neurological signs are present at the start of therapy. therapy with four antitub erculous agents and Treatment: corticosteroids is for at least 12mths and should be supervi sed by a specialist team. the initial pathology is occult haematogenous dissemination 50% will grow Mycobacteria from their CSF and the Mantoux 19_McClure_19.indd 722 11/14/2012 3:51:56 PM TROPICAL INFECTIONS 723 Tropical infections Tropical infections may be present in any child returning from the trop ics (see b p.1026). A general review in the febrile child should follow the process discuss ed in the section on \200\230Acute fever \200\231 (see b pp.696 \200\223701). Malaria \200 Agent: \200 Features: fever (often cyclical, though falciparum is not), di arrhea, vomiting, \202 u-like symptoms, jaundice, anemia, thrombocytopenia. Time occur af ter a few months in children. Diagnosis: thick and thin blood \201 lm should be examined in all children with fever from infected area without prophylaxis. Repeat daily for 3 sampl es if there is a high index of suspicion. Treatment: malaria, although not universally avai lable in the UK. For other forms of malaria consult specialist advice. Plasmodium falciparum (also P. vivax, P. ovale, P. malariae). course: onset usually occurs 7 \200\22310 days after inoculation, but may artesunate is now the \201 rst line therapy for P. falciparum Typhoid \200 Agent: \200 Features: GI symptoms a week later. Splenomegaly, bradycardia, and rose- colored spots on the trunk. Complications include GI perforation, myocarditis, h epatitis, and nephritis. Treatment: therapy following antimicrobial sensitivity testing. Salmonella typhi or paratyphi. fever, headache, cough abdominal pain, myalgia followed by