Clinical presentation of many lesions overlap

April 2001

CHICAGO — Many children’s dermatologic diseases are look-alikes, and careful differential diagnosis is necessary to find the culprit behind pediatric lesions.

Speaking here at the American Academy of Pediatrics, Anthony J. Mancini, MD, of Children’s Memorial Hospital, Northwestern University Medical School, reviewed pediatric cutaneous presentations that could represent several diseases and discussed methods of differentiating them from one another.

---Juvenile xanthogranuloma in a 5-year-old boy.
SOURCE: PEDSDERMATLAS

Pyogenic granuloma, or lobular capillary hemangioma, is “an acquired, benign vascular tumor fairly common in children,” Mancini said. He said it may develop within a port wine stain or other vascular malformation. The name is misleading, he said, as a biopsy shows these lesions to be neither pyogenic or granulomatous. The often dome-shaped, red papules bleed easily and sometimes have a collarette at the base, “which helps you if there’s a question about the diagnosis.” The surface is often moist and friable. These lesions are often treated by excision with electrocautery.

Pyogenic granuloma can resemble spitz nevi and juvenile xanthogranuloma (JXG), Mancini said. Spitz nevi are typical melanocytic lesions in children that are red but are flatter and not as friable. Unfortunately, spitz nevi are often confused with melanoma, Mancini said.

JXG is red in young children, but the lesions normally become lipidized, picking up a yellow-orange hue that can help differentiate them. However, “there is no association with any systemic hypercholesterolemia or hyperlipidemia,” he said. They are benign neoplasms more common in younger children. If multiple JXG lesions are present, he recommended that patients have an eye exam as the lesions can grow in the eye and cause anterior chamber hemorrhage.

Granuloma annulare (GA) is often mistaken for tinea corporis, Mancini said. GA lesions are grouped papules in ringed or annular arrangement, helping differentiate them from tinea, because they do not have scaling, he said. The cause is unknown, although trauma is suspected. Occasionally the lesions can be widely disseminated. The asymptomatic lesions are common over bony prominences. A subcutaneous version is common in children, however.

GA can be treated with topical corticosteroids but often resolves on its own. “So really, just watchful waiting and reassurance,” Mancini said. While it can be confused for tinea corporis, the lesions of t. corporis are more inflamed and often have scaling.

Differentiate vitiligo

---Vitiligo in a 10-year-old child.
SOURCE: PEDSDERMATLAS

Vitiligo is acquired depigmentation in a specific spot, particularly in places such as the inguinal creases and bony prominences. Vitiligo is common, occurring in about 1% of the population. It can be generalized or localized, and about one-half of patients have pediatric onset. Vitiligo is true depigmentation in macules and patches, and not just hypopigmentation such as with pityriasis alba or tinea versicolor. Because it is an autoimmune response against melanocytes, vitiligo may have associated halo nevi or poliosis.

Segmental vitiligo is common in children, and it is a dermatomal distribution of pigment loss that is localized. The disease can be associated with thyroid disease and pernicious anemia. “Treatment of vitiligo is difficult,” Mancini said, and may include topical steroids, psoralen and light therapy or cover-up cosmetics. “I’ve been underwhelmed by everything. Nothing consistently works in every patient.” He said he weighs risks carefully in children, tending to stick to more benign therapies.

Transient neonatal pustular melanosis presents as juicy pustules in the first few days of life on the chin, neck, forehead, palms, soles and buttocks, and 1% to 5% of all black infants have these lesions. The pustules resolve in a few days, although hyperpigmentation may last for a few months. Diagnosis can be assisted by looking for collarettes around the pustules. The child is otherwise well, and the pustules resolve on their own.

This is distinguished from congenital candidiasis, Mancini said, by its lack of inflammation and the fewer number of smaller pustules with neonatal melanosis. Vesicular newborn disease is often problematic to diagnose. “You really have to work these up systematically, and it can be difficult just from skin exam, although there can be some cues.” Also, miliaria or prickly heat, two other lesions that can be confused with melanosis, will both be dispersed in clothing-covered areas and resolve in a few days if the child is kept cool.

“Blueberry muffin” rash

---Blueberry muffin rash.
SOURCE: JAMES H. BRIEN, DO

Congenital cytomegalovirus (CMV) is one of several etiologies for “blueberry muffin” rash, but babies with CMV often have numerous complications including hepatomegaly, splenomegaly, jaundice and hematologic complications. The virus can be isolated from urine or another sterile site, and while ganciclovir (Cytovene, Roche) can be given in extreme cases, traditionally there is no therapy.

CMV can resemble other dermal hematopoiesis disorders, such as rubella, red blood cell deficiencies and parvovirus B19. Also, neoplastic infiltrates can cause further problems, especially congenital leukemia and neuroblastoma.

Nevus sebaceous is a hamartoma of primarily the sebaceous glands and affects 3:1,000 infants. The lesions manifest in a well-demarcated pink, yellow-orange or tan plaque on the nasal bridge, and they are often devoid of hair. The color fades and flattens after infancy, although they change at adolescence, becoming more prominent and greasy.

There is a risk of secondary neoplasm with nevus sebaceous, including a 6% to 15% chance of basal cell carcinoma later in life. The lesions can be excised. While they could be confused with JXG, Mancini said, nevus sebaceous is far more common than JXG.

For more information:

• Mancini A. Look-alikes and controversies in pediatric dermatology. Session E403. Presented at the American Academy of Pediatrics. February 4-8. Chicago.