Skin: Henoch-Schonlein purpura (the most common systemic vasculitis of childhood) Pathogenesis IgA immune mediated leukocytoclastic vasculitis Clinical Palpable purpura manifestations Arthritis/arthralgia Abdominal pain, intussusceptions Renal disease similar to IgA nephropathy Laboratory findings Normal platelet count & coagulation studies Normal to increased creatinine Hematuria +/-RBC casts +/- proteinuria Treatment Supportive (hydration & NSAIDs) for most patients Hospitalizations & systemic glucocorticoids in patients with severe symptoms *Follows an infection and presents with tetrad of palpable purpura on the lower extremities, arthralgias, abdominal pain, and renal disease. Diagnosis requires the presence of lower extremity purpura or petechiae with at least 1 of the following: -Arthritis or arthralgia -Renal involvement -Abdominal pain -Positive histopathology Labs show normal platelet count and mildly elevated creatinine Children with atypical presentations, a renal biopsy may be required: deposition of IgA in the mesangium will be seen. Treatment: Supportive and consists of hydration and pain control with NSAID. Atopic Dermatitis (Eczema) Risk Factors Low humidity Relatives with eczema, allergies, or asthma Clinical Features Infant: face, scalp, and extensors Child adult: flexural Treatment Topical emollients +/- steroid ointment Complications Eczema herpeticum
Vs. Contact dermatitis
Cellulitis/abscess Discomfort interfering with daily activities & sleep Atopic dermatitis: recurrent rash that affects the cheeks, scalp, trunk, and extensor surfaces in infants. It is associated with severe pruritus and most patients have a family hx of atopic disorders (asthma, allergic rhinitis) Contact dermatitis: an inflammatory skin condition causes by contact with an allergen or irritant. Symptoms are similar to atopic dermatitis (including severe pruritus), although they are typically confined to a specific exposed area (e.g. perioral area, hands)
Pathogenesis: epidermal dysfunction due to improper synthesis of stratum corneum components. Allergens can enter the disrupted skin barrier and generate an inflammatory response. Excessive bathing, dry environments, stress, overheating, and irritating detergents can trigger flares. Tx: trigger avoidance, frequent application of thick bland emollients, and use of hypoallergenic cleansers for bathing and laundry. Moderate and severe eczema may require topical anti-inflammatory ointments (e.g. hydrocortisone) Eczema herpeticum- a potential complication of severe atopic dermitis. Superinfection with herpes simplex virus can cause a vesicular eruption on preexisting inflamed skin. Patients often have fever and pain. -Seborrheic dermatitis- “cradle cap” in infants. Adherent greasy scales with a mildly erythematous base are seen on the scalp. -Nevus simplex: * e.g. Macular stain, salmon patch, stork bite, angel kiss * Blanchable, pink red patches that most commonly occur on the eyelid, glabella, and midline of the nape of the neck. They are typically present at birth and fade spontaneously by age 1-2, although neck lesions may persist with no sequelae. Superficial infantile hemaniomans/ strawberry hermangiomas: benign capillary tumors of childhood. They appear during the first weeks of life, initially grow rapidly, and typically regress spontaneously. Some lesion may require treatment with beta blockers.
Seborrheic dermatitis Clinical Features Associations Pathogenesis
Treatment
Peaks in infancy & adulthood Erythematous plaques &/or yellow, greasy scales Located on scalp, face (e.g. eyebrows/eyelids, posterior ears, nasolabial folds), umbilicus, diaper area Malassezia spp Affects areas with numerous sebaceous glands. In infant, these areas include the scalp (“cradle cap”), eyelids, nasolabial folds, postauricular area, and umbilicus First line: Emollients, nonmedicated shampoos Second line: Topical antifungals or low potency glucocoritcoids
Tinea capitis: fungal infection of the scalp that causes pruritic patchy, fine, white scales that resemble SD (seborrheic dermatitis). But, it does not involve the eyebrows or nasolabial fols and is uncommon in the first year. Psoriasis: Chronic inflammatory disorder that affects the extensor surfaces of the elbows and knees. Oral Isotretinoin Therapy Clinical use
Pathophys
Side Effects
Treats severe, recalcitrant nodulocystic acne associated with significant scarring that has not responded to other therapies including systemic antibiotics Retinoids inhibit follicular epidermal keratinization, which results in loosening of the keratin plugs of comedones and facilitating their expulsion Retinoids also reduce the size of sebaceous glands and inhibit sebum production Pseudotumor cerebri Hyperlipidemia Chelitis, dry skin Myalgias Tertogenic: spontaneous
CI
SSS (Staphylococcal scalded skin syndrome)
Scarlet fever Impetigo
Erysipelas Erythema multiforme
abortion, fetal malformations Don’t give with tetracyclin due to risk of idiopathic intracranial HTN- pseudotumor cerebri.
Exfoliative toxin targets desmoglein 1, which is responsible for keratinocyte adhesion in the superficial epidermis Cultures are sterile (toxin mediated) Eliminate inciting focus of infection with appropriate anti-staph antibiotics Mortality rate low in kids, high in adults
S. aureus or group A Bhemolytic streptococcu s
MC infectious
Prodrome: fever, irritability, skin tenderness Erythema starts on face and generalized within 24-28 hours Superficial flaccid blisters develop, with flexural accentuation and perioral crusting NIkolsky sign is positive (gentle lateral pressure on the skin surface adjacent to a blister causes slipping and detachment of a superficial layer of skin). Blisters are fragile and unroofed reveal a moist erythematous base Subsequent scaling and desquamation continue for 5 days Resolves within 1-2 weeks Localized epidermal infection Bullous and nonbullous variants Acute, self limited reaction
agent is Herpes simplex
Targetoid papule or plaque Arofacial distribution & palmar involvement Mucosal lesions and systemic symptoms also seen Targetoid lesions of EM may have central bulla, but Nikolsky sign is negative
