Title: GZ / The Grenz Zone Season 2 / 24 Toxin-Mediated Rashes
Tags: GZ DermnetNZ

Q: Staph scalded skin syndrome is caused by a specific strain of Staphylococcus called Phage Group 2, Strains [number] and [number]
A: 55; 71
Back Extra: These strains produce exfoliatoxins A & B that cleave epidermal protein, desmoglein 1, which is responsible for keratinocyte adhesion. This causes detachment of the superficial epidermis leading to skin sloughing
Pearl: The same staph toxins cause bullous impetigo through the same mechanism, however, in buLLous impetigo, Staph only grows locaLLy, whereas in Scalded Skin Syndrome, it diSSeminates systemically

Q: Clinically, staph scalded skin syndrome presents in infants and young kids <6 y/o or adults with immunosuppresion or chronic renal failure. Look for fevers, [...], erythema, and superficial blistering and desquamation
A: skin pain
Back Extra: 1. Rash classically starts on the face with radial fissures around the mouth, eyes, and nose
2. More severe in the intertriginous areas (armpits), considering there is more friction in these areas
3. Lack of oral involvement (>desmoglein 3 compensates for loss of desmoglein 1 here)

Q: Diagnosis of staph scalded skin syndrome is with [...] and/or [...]
A: blood culture; biopsy
Back Extra: Skin culture is commonly negative due to the fact that the toxin disseminates to the skin from a distant site

Q: On histology, staph scalded skin syndrome will demonstrate superficial splitting AT or JUST BELOW the [...]
A: stratum granulosum
Back Extra: Full thickness epidermal necrosis is ABSENT (if present, think SJS or TEN)

Q: Treatment of staph scalded skin syndrome is [...] and supportive care
A: antibiotics
Back Extra: Abx examples: nafcillin, 1st or 2nd gen. cephalosporins, or vancomycin
Supportive care: electrolytes, IV fluids, gentle wound care with nonadherent dressings

Q: Toxic Shock Syndrome is caused by either [bacteria] or [bacteria]
A: Staph; Strep
Back Extra: Staph: Toxin-1 (TSST-1); more common, less severe
Strep: Group A Strep makes strep pyrogenic toxins A,B,C; less common, more severe
These toxins act as superantigens → cytokine storm → nonspecific T cell activation

Q: Clinically, toxic shock syndrome presents as a healthy adult with a [...] such as a superabsorbent tampon, surgical packing, or mesh that suddenly has high fevers, headaches, GI complaints → hypotensive shock w/ internal organ involvement
A: foreign body
Back Extra: Internal organ involvement: renal impairment, ARDS, liver failure, DIC

Q: Diagnosis of toxic shock syndrome is with [...] and/or [...]
A: blood culture; skin culture

Q: Toxic shock syndrome caused by [bacteria] will present with a scarlatiniform rash (diffuse redness with pinpoint papules) that classically starts on the trunk and then generalizes. Erythematous rash desquamates 1-3 weeks later
A: Staph
Back Extra: Can involve palm and soles
Pearl: Unlike scalded skin syndrome, toxic shock syndrome can involve mucosal surfaces leading to strawberry tongue and inflammed conjunctiva

Q: Toxic shock syndrome caused by [bacteria] typically starts off with a soft tissue infection like necrotizing fasciitis leading to extremity pain
A: Strep
Back Extra: Much less likely to have a scaratiniform rash
More severe that staph, mortality 30-60%

Q: Treatment for toxic shock syndrome consists of [...], [...], and extensive supportive care
A: antibiotics; surgical debridement

Q: Kawasaki Disease is a small to medium vessel vasculitis that classically presents in [...] that are < 5 years old
A: Asians

Clinical presentation of Kawasaki disease can be remembered with the pneumonic CRASH & Burn
C: Conjunctivitis
R: Rash
A: Adenopathy (Cervical lymphadenopathy
S: Strawberry tongue
H: Hand/Feet erythema & edema
B: Fever >39 C for > 5 days
Back Extra: Rash: Morbilliform, urticarial with sandpapery papules on a background of erythema. Accentuates with friction (groin)
Pearl: Fevers usually last at least 1 week and do not respond well to Tylenol

Q: What is a complication of Kawasaki disease that can occur several weeks after symptom onset in around 25% of untreated kids?
[...]
A: Coronary artery aneurysms

Diagnosis of Kawasaki disease is with clinical presentation and lab abnormalities (WATCH)
W: elevated WBC
A: Anemia
T: Thrombocytosis vs Thrombocytopenia
C: CRP
H: Hypoalbuminemia
Back Extra: REMEMBER: for diagnosis with clinical presentation you must have a fever of at least 5 days + 4/5 other diagnostic criteria in CRASH pneumonic

Q: Treatment of Kawasaki disease is 80-100mg/kg/day of [...] and 2g/kg infusion of [...] over 12 hours
A: Aspirin; IVIG
Back Extra: Aspirin is divided into 4 doses. Provide for 2-3 days after fever ends, then give 3-5 mg/kg/day until labs normalize and ECHO is negative

Q: Scarlet Fever usually presents in 1-10 year olds and is caused by [specific bacteria] via respiratory droplets
A: Strep (Group A)
Back Extra: Group A Strep produces strep pyrogenic toxins A,B,C; just like in Toxic Shock Syndrome

Q: Clinically, Scarlet Fever presents with classic strep throat sxs (fever, chills, headache, red swollen tonsils w/ exudate), palate petechiae, strawberry tongue,  and a fine [...] rash w/ fine macules and papules on the trunk & extremities lasting 4-5 days with NO rhinorrhea or cough
A: sandpaper
Back Extra: Look for Pastia's lines: accentuations of the rash in flexural areas with linear petechiae

Q: Some complications of Scarlet Fever are [...] and [...]
A: acute glomerulonephritis; rheumatic fever
Back Extra: JONES: joints (polyarthritis), pancarditis, subQ extensor nodules, erythema marginatum, Syndenham Chorea (flinching movements)

Q: Diagnosis of Scarlet Fever is with clinical presentation and [...]
A: throat culture

Q: Treatment of Scarlet Fever consists of [general treatment]
A: antibiotics
Back Extra: Amoxicillin is 1st line. If allergy to penicillins: erythromycin, clindamycin, or 1st gen cephalosporin