Allergic contact dermatitis Irritant contact dermatitis Papular urticaria Erythema multiforme Guttate psoriasis Pityriasis lichenoides Lichen nitidus EVALUATION AND DECISION In approaching a child with an exanthem, a careful history and full examination of all cutaneous surfaces will often be all that is required to make a diagnosis The most important historical features include the duration of the rash (acute or chronic), initial distribution, extent of spread (generalized or localized), ill contacts (including sexual partners), and any associated systemic symptoms, including fever The physical examination should include a careful systematic inspection of all mucocutaneous surfaces, with special attention paid to involvement of the oropharynx, palms and soles, extensor or flexor surfaces, scalp, and trunk TABLE 88.2 POTENTIALLY LIFE-THREATENING ILLNESSES ASSOCIATED WITH DIFFUSE MORBILLIFORM ERUPTION Rocky Mountain spotted fever Kawasaki disease Erythema multiforme Dengue fever Rubeola Ehrlichiosis Drug reaction with eosinophilia and systemic symptoms (DRESS)