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FIGURE 88.12 Lichen nitidus One can reassure parents that three-fourths of lesions clear spontaneously within a 2-year period Recurrences are common until children outgrow this tendency FIGURE 88.13 Granuloma annulare Lupus Neonatal lupus and systemic lupus can sometimes be composed of annular plaques Lupus has a varied appearance depending on type and whether it is skin limited or systemic For more discussion please see Chapter 69 Rash: Neonatal for discussion of neonatal lupus and Chapter 67 Rash: Vesiculobullous for discussion of bullous lupus NODULES Nodules in the skin can be difficult to diagnose and many require a skin biopsy There are a few inflammatory conditions of the skin that are characteristically nodules and should not be missed Panniculitis Erythema Nodosum Erythema nodosum seems to be a hypersensitivity reaction leading to inflammation of the subcutaneous fat and may be related to infection (streptococci, tuberculosis, coccidioidomycosis, histoplasmosis), inflammatory bowel disease, sarcoidosis, and medications (e.g., oral contraceptives) The exact immunologic mechanism has not been clarified The entity occurs predominantly in adolescents during the spring and fall Women are affected more often than men The lesions of erythema nodosum appear as deep, tender, erythematous nodules, or plaques on the extensor surfaces of the extremities The sedimentation rate is generally elevated and usually returns to normal with disappearance of the eruption, unless an underlying disease is present The reaction usually lasts to weeks Treatment should be directed toward the cause when and if established; otherwise, it is symptomatic (nonsteroidal anti-inflammatory drugs and antihistamines) Corticosteroids should be avoided, except in severe cases after an underlying infection has been ruled out Cold Panniculitis Cold panniculitis is caused by cold injury to fat During the cold of winter, infants and some older children develop red, indurated nodules and plaques on exposed skin, especially on the face The subcutaneous fat in infants and some children solidifies more readily at a higher temperature than that of an adult because of the relatively greater concentration of saturated fats Infants who hold ice chips or popsicles in their mouths are also susceptible to this phenomenon (“popsicle panniculitis”) The lesions gradually soften and return to normal over or more weeks Treatment is unnecessary Generalized Macules and Papules/Morbilliform Eruptions The causes of morbilliform eruptions rashes are diverse ( Table 88.1 ) and range from benign to life-threatening ( Table 88.2 ) Common causes include viral exanthems and drug reactions The diagnostic approach to these disorders is based on the presence or absence of fever, characteristic clinical appearance, location, chronicity, and medication history Some of these conditions have very characteristic clinical appearances ( Table 88.3 ); however, manifestations of these illnesses can be sufficiently variable that a proportion of the cases are difficult to diagnose