Dr. Huang presented information about rare but important causes of neonatal blistering, diaper rash, and solitary skin nodules.
First, Dr. Huang described rare causes of neonatal blistering including epidermolysis bullosa (EB) and incontinentia pigmenti (IP). EB encompasses a spectrum of genetic disorders that cause skin fragility; the genetic mutations determine the severity of disease and whether there is internal involvement. Severity cannot be determined by clinical presentation. EB is suspected when blisters occur in areas of friction or if there is nail involvement. Workup includes skin biopsy of newly induced blisters for immunofluorescent mapping and genetic testing.
IP is an X-linked dominant disorder affecting the skin, eyes, and central nervous system. IP is suspected when blisters occur in a blaschkoid distribution. Because IP is lethal in males, presentation of a female patient whose mother has a history of miscarriages can indicate this disease. IP can be diagnosed based solely on rash and skin biopsy results, without genetic testing. Early diagnosis and treatment can significantly reduce morbidity and mortality by preventing seizures and promoting development.
Second, Dr. Huang discussed rare causes of diaper rash, including zinc deficiency and Langerhans cell histiocytosis (LCH). Signs and symptoms of zinc deficiency include diaper rash, periorificial rash (around the mouth, nose, or eyes), acral rash, alopecia, diarrhea, decrease in appetite, frequent infections, and decrease in energy. Zinc deficiency can be caused by low intake or poor absorption. Workup includes genetic testing and zinc testing of the patient, maternal serum, and breastmilk.
Patients with LCH present with crusted petechial or purpuric papules in skin folds and scalp. Mucous membranes may be involved, especially in multisystem disease. Workup includes skin biopsy, physical exam, complete blood count, liver function test, abdominal ultrasound, and skeletal survey. Patients with skin-limited LCH have a good prognosis and may not need treatment.
Third, Dr. Huang presented rare causes of neonatal solitary skin nodules, including Kaposiform hemangioendothelioma, rhabdomyosarcoma, and infantile fibrosarcoma. Signs that a solitary tumor may be malignant include: presence since birth, persistence after 6–9 months of age, firm to the touch, and rapid growth. Workup includes imaging and biopsy.