ABD Pediatric Dermatology key terms

A chronic inflammatory disorder of the pilosebaceous unit in which follicular keratinization, sebum production, Cutibacterium acnes colonization, and inflammation produce comedones and papulopustules, most often on the face, chest, and back during adolescence.

A plug of keratin and sebum within a dilated follicular orifice; open comedones (blackheads) have a widened dark surface, while closed comedones (whiteheads) are small pale papules with a narrow opening.

A chronic relapsing pruritic inflammatory skin disease with impaired skin barrier function, typically beginning in infancy with eczematous patches on the cheeks and extensor surfaces and later favoring flexural creases.

A structural protein of the stratum corneum that aggregates keratin filaments and contributes to the skin barrier; loss-of-function mutations are associated with atopic dermatitis and ichthyosis vulgaris.

A disseminated herpes simplex virus infection superimposed on damaged skin, usually atopic dermatitis, producing monomorphic punched-out vesicles and erosions with fever; it is a medical emergency requiring prompt antiviral therapy.

A common benign condition of childhood and adolescence presenting as poorly demarcated hypopigmented, mildly scaly patches on the face and upper arms, often in children with atopic diathesis, and usually resolving spontaneously.

A chronic inflammatory eruption of sebaceous-rich areas such as the scalp, eyebrows, and nasolabial folds, producing greasy yellowish scale and erythema; in infants it appears as cradle cap and may overlap with diaper-area involvement.

Infantile seborrheic dermatitis of the scalp, showing adherent greasy yellowish scales and crusts on an erythematous base, generally asymptomatic and self-limited in the first months of life.

Inflammation of the skin covered by a diaper caused by prolonged contact with urine and feces, occlusion, and friction; irritant contact type is most common, with Candida and bacterial superinfection as frequent complications.

A severe irritant diaper dermatitis with sharply demarcated, beefy-red, eroded or ulcerated papules and plaques, often with raised borders, occurring where urine and feces contact the skin most intensely.

A benign condition of infancy, usually linked to chronic diaper occlusion and candidiasis, featuring firm violaceous or reddish nodules in the diaper area that resolve after the irritant exposure is removed.

A sweat-retention eruption caused by obstruction of eccrine ducts, presenting in infants as tiny pruritic papules or vesicles on the neck, trunk, and flexures in warm, humid conditions; subtypes include crystallina, rubra, and profunda.

A common benign self-limited eruption of term newborns, appearing in the first days of life as blotchy erythematous macules with central yellow-white papules or pustules on the trunk and extremities, sparing palms and soles.

A benign newborn eruption present at birth, consisting of superficial pustules that rupture to leave collarettes of scale and hyperpigmented macules, most often on the chin, neck, and lower abdomen of dark-skinned infants.

An acneiform eruption of the first weeks of life with papules and pustules on the face and scalp, associated with Malassezia colonization and generally resolving without scarring or specific therapy.

A benign vascular tumor appearing in the first weeks of life that proliferates for several months and then slowly involutes, ranging from small superficial lesions to deep or segmental forms that may require treatment.

An association of large segmental facial hemangiomas with posterior fossa brain malformations, arterial anomalies, cardiac defects or coarctation, and eye abnormalities; evaluation of affected infants is warranted.

A nonselective beta-adrenergic antagonist used as first-line systemic therapy for problematic infantile hemangiomas, requiring baseline cardiopulmonary assessment and monitoring during initiation and dose increases.

A congenital capillary malformation presenting as a geographic pink-to-purple patch that does not involute, may thicken with age, and can be associated with Sturge-Weber syndrome when involving the ophthalmic trigeminal distribution.

A neurocutaneous disorder combining a facial port-wine stain in the V1 distribution with ipsilateral leptomeningeal vascular malformation, seizures, glaucoma, and developmental delay.

An acute medium-vessel vasculitis of young children with fever, conjunctivitis, oral mucosal changes, polymorphous rash, extremity changes, and cervical lymphadenopathy, carrying risk of coronary artery aneurysms.

A red, glossy tongue with prominent engorged papillae, classically seen in Kawasaki disease and scarlet fever as part of mucocutaneous inflammation.

A streptococcal infection-associated illness with fever, sore throat, a sandpapery erythematous rash with circumoral pallor, and a strawberry tongue, caused by pyrogenic exotoxin-producing group A Streptococcus.

An acute immune-mediated eruption with target lesions, often triggered by herpes simplex virus or other infections, typically favoring acral sites; severe mucosal involvement defines erythema multiforme major.

A severe mucocutaneous reaction, usually drug-induced, with epidermal detachment of less than 10 percent of body surface area, prominent mucosal erosions, fever, and high risk of ocular and systemic complications.

The most severe form of epidermal necrolysis, typically medication-triggered, with widespread full-thickness epidermal detachment exceeding 30 percent of body surface area and high mortality requiring intensive supportive care.

Dermatophyte infection of the scalp hair and follicles, common in children, producing scaling, patches of hair loss, broken hairs, and sometimes boggy inflammatory masses; systemic antifungal therapy is required.

A severe inflammatory dermatophyte infection of the scalp forming a boggy, purulent, tender mass with hair loss, representing an exaggerated host immune response and often leading to scarring if untreated.

Dermatophyte infection of glabrous skin, presenting as annular scaly plaques with central clearing and an active raised border, often acquired from pets, soil, or person-to-person contact.

A superficial Malassezia yeast infection of the stratum corneum producing hypo- or hyperpigmented finely scaling macules on the trunk and shoulders, common in humid climates and adolescence.

A poxvirus infection producing small dome-shaped papules with central umbilication, common in children and spread by direct contact; lesions are self-limited but may persist for months.

A common wart caused by human papillomavirus, appearing as a hyperkeratotic papule with rough surface and thrombosed capillaries, frequently on the hands and feet of children.

A superficial bacterial skin infection, usually staphylococcal or streptococcal, presenting as honey-crusted erosions or bullae, most common in young children and highly contagious.

A toxin-mediated illness of infants and young children caused by exfoliative toxin-producing Staphylococcus aureus, producing diffuse tender erythema followed by superficial epidermal peeling with a positive Nikolsky sign and mucosal sparing.

Separation of the upper epidermis with gentle lateral pressure on the skin, indicating loss of epidermal cohesion and seen in pemphigus, toxic epidermal necrolysis, and staphylococcal scalded skin syndrome.

A chronic immune-mediated papulosquamous disorder with sharply demarcated erythematous plaques bearing silvery scale, commonly on extensor surfaces and scalp; pediatric variants include guttate and diaper-area forms.

Pinpoint bleeding that appears when scale is removed from a psoriatic plaque, reflecting the elongation and superficiality of dermal papillary capillaries.

A rare erythroderma of infancy with severe seborrheic-like scaling, diarrhea, and failure to thrive, historically linked to complement deficiency and now often considered part of severe atopic or immunodeficiency states.

The most common inherited ichthyosis, usually autosomal dominant with filaggrin loss, producing fine white scale on extensor surfaces, prominent palmar markings, and sparing of flexures.

An intensely pruritic vesicular eruption with grouped papules on extensor surfaces, representing cutaneous gluten sensitivity and associated with celiac disease.

An immune-mediated enteropathy triggered by dietary gluten, causing malabsorption and associated with dermatitis herpetiformis and other autoimmune conditions.

A hypersensitivity panniculitis producing tender erythematous nodules on the shins, often triggered by streptococcal infection, medications, or inflammatory bowel disease in children.