A 5-month-old girl was noted to have skin lesions on her right ear. A few of the lesions had been present at birth, and others had been noted later. Some of the lesions had become acutely inflamed and enlarged. The girl is otherwise asymptomatic, with no associated neurologic or skeletal abnormalities. The prenatal and birth history were uneventful.
The girl received a diagnosis of nevus comedonicus, a rare skin condition that affects the hair follicles and is considered a hamartoma of the pilosebaceous unit.1 It is characterized by situated, raised papules on the skin, causing blackheads. It presents at birth in 50% of cases, or develops in early childhood.2
Nevus comedonicus typically occurs unilaterally, with a predilection for face, neck, cheek, back, and calves.1,3 Rarely, it can present on the penis.3 Lesion growth is accelerated during puberty, and the condition can be complicated by secondary infection.1 In rare cases, when nevus comedonicus occurs along with bone, brain, and eye abnormalities, it is known as nevus comedonicus syndrome.1,4
Histopathologic findings on skin biopsy typically show large, grouped, dilated, keratin-filled follicular ostia, with rudimentary glands at the base of follicular invaginations.2
Malignant transformation is rare; thus, nevus comedonicus does not require aggressive treatment. Treatment options include topical corticosteroids, keratolytic agents, and lasers; complete surgical resection is considered the treatment of choice.2
1. Bhullar A, Shamsudin N. Images in clinical medicine: nevus comedonicus. N Engl J Med. 2015;372(26):2541.
2. Tchernev G, Ananiev J, Semkova K, Dourmishev LA, Schönlebe J, Wollina U. Nevus comedonicus: an updated review. Dermatol Ther (Heidelb). 2013;3(1):33-40.
3. Chhabra N, Pandhi D, Verma P, Sharma S. Inflammatory nevus comedonicus with epidermoid cyst. Indian J Dermatol. 2014;59(4):422.
4. Ferrari B, Taliercio V, Restrepo P, Luna P, Abad ME, Larralde M. Nevus comedonicus: a case series. Pediatr Dermatol. 2015;32(2):216-219.