Differential diagnosis		Distinguishing features
Tinea corporis (annular lesions with well-defined, scaly, often reddish margins; commonly pruritic)
	Annular psoriasis	Gray or silver scale; nail pitting; 70% of affected children have family history of psoriasis2
	Atopic dermatitis	Personal or family history of atopy; less likely to have active border with central clearing; lesions may be lichenified
	Erythema multiforme	Target lesions; acute onset; no scale; may have oral lesions
	Fixed drug eruption	Dusky; erythematous; usually single, nonscaly lesion; most often triggered by sulfa, acetaminophen, ibuprofen, or antibiotic use
	Granuloma annulare	No scale, vesicles, or pustules; nonpruritic; smooth; commonly on dorsum of hands or feet
	Lupus erythematosus (subacute cutaneous)	Sun-exposed areas; multiple annular lesions; female-to-male ratio 3:13
	Nummular eczema	More confluent scale; less likely to have central clearing
	Pityriasis rosea herald patch	Typically an adolescent with a single lesion on neck, trunk, or proximal extremity; pruritus of herald patch is less common; progression to generalized rash in one to three weeks
	Seborrheic dermatitis	Greasy scale on erythematous base with typical distribution involving nasolabial folds, hairline, eyebrows, postauricular folds, chest; annular lesions less common
Tinea cruris (usually occurs in male adolescents and young men; spares scrotum and penis)
	Candidal intertrigo	Involves scrotum; satellite lesions; uniformly red without central clearing
	Erythrasma	Red-brown; no active border; coral red fluorescence with a Wood lamp examination
	Inverse psoriasis	Red and sharply demarcated; may have other signs of psoriasis such as nail pitting
	Seborrheic dermatitis	Greasy scale on erythematous base with typical distribution involving nasolabial folds, hairline, eyebrows, postauricular folds, chest; annular lesions less common
Tinea pedis (rare in prepubertal children; erythema, scale, fissures, maceration; itching between toes extending to sole, borders, and occasionally dorsum of foot; may be accompanied by tinea manuum [“one-hand, two-feet” involvement] or onychomycosis)
	Contact dermatitis	Distribution may match footwear; usually spares interdigital skin
	Dyshidrotic eczema	“Tapioca pudding” vesicles on lateral aspects of digits; often involves hands
	Foot eczema	May have atopic history; usually spares interdigital skin
	Juvenile plantar dermatosis	Shiny taut skin involving great toe, ball of foot, and heel; usually spares interdigital skin
	Psoriasis	Involvement of other sites; gray or silver scale; nail pitting; 70% of affected children have family history of psoriasis2
Tinea capitis (one or more patches of alopecia, scale, erythema, pustules, tenderness, pruritus, with cervical and suboccipital lymphadenopathy; most common in children of African heritage)
	Alopecia areata	Discrete patches of hair loss with no epidermal changes (i.e., no scale); total loss of hair or fine miniature hair growth; exclamation point hairs; no crusting; no inflammation; possible nail pitting
	Atopic dermatitis	Personal history or family history of atopy; less often annular; lymphadenopathy uncommon; alopecia less common
	Bacterial scalp abscess	Alopecia less likely; hair pluck is painful
	Psoriasis	Gray or silver scale; nail pitting; 70% of affected children have family history of psoriasis2; involvement of other sites
	Seborrheic dermatitis	Alopecia uncommon; lymphadenopathy uncommon; greasy scale; typical distribution involving nasolabial folds, hairline, eyebrows, postauricular folds, chest
	Trichotillomania	No scale; commonly involves eyelashes and eyebrows; hairs of varying lengths
Onychomycosis (discolored [white, yellow, brown], thickened nail with subungual keratinous debris and possible nail detachment; often starting with great toe but can involve any nail)
Other nail dystrophies, most commonly associated with repeated low-grade trauma, psoriasis, or lichen planus		Appearance can be indistinguishable from onychomycosis; may have other manifestations of alternate diagnosis