Sarecycline is a narrow-spectrum tetracycline-derived antibiotic. It is specifically designed for the treatment of acne, and was approved by the FDA in October 2018 for the treatment of inflammatory lesions of non-nodular moderate to severe acne vulgaris in patients 9 years of age and older. Two randomized and well-controlled clinical trials reported efficacy data on both facial and truncal acne (back and chest). Efficacy was assessed in a total of 2002 subjects 9 years of age and older. Unlike other tetracycline-class antibiotics, sarecycline has a long C7 moiety that extends into and directly interact with the bacterial messenger RNA (mRNA). The spectrum of activity is limited to clinically relevant Gram-positive bacteria, mainly Cutibacterium acnes, with little or no activity against Gram-negative bacterial microflora commonly found in the human gastrointestinal tract. Sarecycline has not been tested in spirochetes. References
External links
"Sarecycline". Drug Information Portal. U.S. National Library of Medicine.
Staphylococcal scalded skin syndrome (SSSS) is a dermatological condition caused by Staphylococcus aureus. Signs and symptoms
The disease presents with the widespread formation of fluid-filled blisters that are thin walled and easily ruptured, and the patient can be positive for Nikolskys sign. Ritters disease of the newborn is the most severe form of SSSS, with similar signs and symptoms. SSSS often includes a widespread painful erythroderma, often involving the face, diaper, and other intertriginous areas. Extensive areas of desquamation might be present. Perioral crusting and fissuring are seen early in the course. Unlike toxic epidermal necrolysis, SSSS spares the mucous membranes. It is most common in children under 6 years, but can be seen in adults who are immunosuppressed or have kidney failure. Pathophysiology
The syndrome is induced by epidermolytic exotoxins (exfoliatin) A and B, which are released by S. aureus and cause detachment within the epidermal layer, by breaking down the desmosomes. One of the exotoxins is encoded on the bacterial chromosome, while the other is encoded on a plasmid. These exotoxins are proteases that cleave desmoglein-1, which normally holds the granulosum and spinosum layers together, similar to the pathophysiology of the autoimmune skin disease, pemphigus vulgaris. Diagnosis
SSSS is a clinical diagnosis. This is sometimes confirmed by isolation of S. aureus from blood, mucous membranes, or skin biopsy; however, these are often negative. Skin biopsy may show separation of the superficial layer of the epidermis (intraepidermal separation), differentiating SSSS from TEN, wherein the separation occurs at the dermo-epidermal junction (subepidermal separation).