It is also effective against Yersinia pestis (the infectious agent of bubonic plague), and is prescribed for the treatment of Lyme disease, ehrlichiosis, and Rocky Mountain spotted fever.Doxycycline is indicated for treatment of:
Rocky Mountain spotted fever, typhus fever and the typhus group, Q fever, rickettsialpox, and tick fevers caused by Rickettsia
Respiratory tract infections caused by Mycoplasma pneumoniae
Lymphogranuloma venereum, trachoma, inclusion conjunctivitis, and uncomplicated urethral, endocervical, or rectal infections in adults caused by Chlamydia trachomatis
Psittacosis
Nongonococcal urethritis caused by Ureaplasma urealyticum
Relapsing fever due to Borrelia recurrentis
Chancroid caused by Haemophilus ducreyi
Plague due to Yersinia pestis
Tularemia
Cholera
Campylobacter fetus infections
Brucellosis caused by Brucella species (in conjunction with streptomycin)
Bartonellosis
Granuloma inguinale (Klebsiella species)
Lyme diseaseWhen bacteriologic testing indicates appropriate susceptibility to the drug, doxycycline may be used to treat these infections caused by Gram-negative bacteria:
Escherichia coli infections
Enterobacter aerogenes (formerly Aerobacter aerogenes) infections
Shigella species infections
Acinetobacter species (formerly Mima species and Herellea species) infections
Respiratory tract infections caused by Haemophilus influenzae
Respiratory tract and urinary tract infections caused by Klebsiella speciesSome Gram-positive bacteria have developed resistance to doxycycline. Up to 44% of Streptococcus pyogenes and up to 74% of S. faecalis specimens have developed resistance to the tetracycline group of antibiotics. Up to 57% of P. acnes strains developed resistance to doxycycline.
Rarely, bites may cause widespread symptoms, with occasional fatalities.There are a few spiders that can bite human skin and cause a skin reaction, but spiders are blamed for many more reactions. In particular the misdiagnosis of infections and other skin ailments are commonly attributed to brown recluses. Cause
Spiders do not feed on humans and typically bites occur as a defense mechanism. This can occur from unintentional contact or trapping of the spider. Most spiders have fangs too small to penetrate human skin. Most bites by species large enough for their bites to be noticeable will have no serious medical consequences.Medically significant spider venoms include various combinations and concentrations of necrotic agents, neurotoxins, and pharmacologically active compounds such as serotonin. Worldwide only two spider venoms have impact on humans—those of the widow and recluse spiders. Unlike snake and scorpion envenomation, widow and recluse species bites rarely have fatal consequences. In addition to the widespread widow and recluse spiders, some spider families found exclusively in remote tropical regions have a lethal neurotoxic venom: the wandering spider in Brazil and the funnel web in Australia. However, due to limited contact between these spiders and humans, deaths have always been rare, and since the introduction of anti-venom in Australia, there have been no funnel web related deaths. Pathophysiology
A primary concern of the bite of a spider is the effect of its venom. A spider envenomation occurs whenever a spider injects venom into the skin.