Table 2.

Diagnosis of atopic dermatitis: common mimics, overlaps, and complications and relative prevalence by age group.

	Diagnosis	Relative Prevalence
		Infants	Children	Adolescents/Adults
Inflammatory Skin Conditions (See Section 2)	seborrheic dermatitis	common	uncommon	common
	psoriasis	less common	less common	common
	nummular dermatitis	less common	common	less common
	contact dermatitis a	common	common	common
	dermatographism a	less common	common	common
	pityriasis alba a	common	common	uncommon
	overlap (see Section 2.7)	common	common	common
Infections (See Section 3)	impetigo a	common	common	less common
	secondary syphilis	rare	rare	rare
	molluscum dermatitis a	common	common	less common
	eczema herpeticum a	uncommon	uncommon	rare
	eczema vaccinatum a	rare	rare	rare
	eczema coxsackium a	emerging	emerging	rare
	viral exanthem	common	common	less common
	tinea (as AD mimic)	uncommon	uncommon	uncommon
	candidiasis	common	less common	less common
Infestations (See Section 4)	scabies (prevalence varies by region)	may be common	may be common	may be common
Genetic Disorders (See Section 6)	keratosis pilaris	less common	common	not common
	ichthyosis vulgaris a	common	common	common
Immunodeficiency Disorders (See Section 7)	HIV/AIDS-related skin changes (prevalence varies by region)	less common	less common	may be common
Other (See Section 9)	drug eruptions	less common	common	common

^a Frequent complication of AD.