Diagnostic pearls for neonatal histiocytosis include refractory or purpuric seborrheic dermatitis, eroded papules or nodules in areas of skin flexion, and crusted papules on the palms and soles.
Noninfectious bullous disorders include sucking blisters, a common and benign disorder caused by vigorous sucking of the affected body part by the fetus in utero.
Epidermolysis bullosa (EB) is an inherited mechanobullous disease and another source of noninfectious bullae. Infants with this condition present with blistering and open erosions, Dr. Mancini said. In addition, they may have large areas of aplasia cutis and mucosal involvement. The subtype of EB that the patient has determines the clinical presentation.
Mastocytosis is caused by an increase in cutaneous mast cells, and it can manifest as bullous lesions in infants. It presents with tan macules and papules that may have a “peau d'orange” (orange peel) appearance. Flushing, irritability, diarrhea, and respiratory distress are other potential features of this condition.
Finally, another category of noninfectious diagnoses are those that refer to a “red, scaly baby,” a neonate or infant who presents with widespread erythema and scaling. Diagnoses of this presentation include seborrheic dermatitis, atopic dermatitis, and psoriasis, Dr. Mancini said.
However, other conditions to consider include nutritional or metabolic disorders, immunodeficiency, ichthyoses, or ectodermal dysplasia.
“Cradle cap” is a characteristic presentation of seborrheic dermatitis in infants, which also may involve the groin, the umbilicus, and areas of skin flexion. By contrast, atopic dermatitis tends to spare the diaper area, and often involves the extremities.
Cradle cap can often be associated with a S. aureus colonization or infection. Psoriasis has some clinical overlap with seborrhea; it often occurs in the diaper area and scalp, and it can be triggered by infection with group A streptococcus.
Consider immunodeficiency in any baby with eczema or seborrheic dermatitis that resists treatment, Dr. Mancini said.
Another cause of red, scaly lesions in the infant is neonatal lupus, a diagnosis which should not be missed. It presents as scaly, erythematous patches and plaques that are sometimes diffuse, but most often occur in the periorbital area, which creates a “raccoon eye” presentation. Atrophy or telangiectasia also may be present. The mothers of children with neonatal lupus likely have anti-Ro, anti-La, or anti-U1 ribonucleoprotein antibodies, he noted, and the condition can be associated with congenital heart block.