Background
Dermatosis papulosa nigra (DPN) is a benign cutaneous condition common among blacks. It is usually characterized by multiple, small, hyperpigmented, asymptomatic papules on the face of adult blacks. Histologically, dermatosis papulosa nigra resembles seborrheic keratoses. The condition may be cosmetically undesirable to some patients. See the image below.
Pathophysiology
The pathophysiology of dermatosis papulosa nigra is not known. The occasional positive family history may suggest a genetic propensity.
Epidemiology
Frequency
Whereas earlier US studies revealed a 10% frequency in adult blacks, more recent data suggest a frequency of approximately 35% in this population. Data pertaining to the international frequency of dermatosis papulosa nigra are insufficient.
Race
Dermatosis papulosa nigra affects up to 35% of the African American population. [1] Blacks with a fair complexion have the lowest frequency of involvement. [2] Dermatosis papulosa nigra also occurs among Asians, although the exact incidence is unknown.
Sex
Females are affected more frequently than males. [2]
Age
Dermatosis papulosa nigra usually begins in adolescence and is rare in persons younger than 7 years. [3] The incidence of dermatosis papulosa nigra, as well as the number and size of individual lesions, increases with age.
Prognosis
The prognosis for patients with dermatosis papulosa nigra is excellent since it is not a premalignant condition nor is it associated with any underlying systemic disease. However, lesions of dermatosis papulosa nigra show no tendency to regress spontaneously, and they gradually may increase in number and size with age.
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Dermatosis papulosa nigra. Courtesy of DermNet New Zealand (http://www.dermnetnz.org/assets/Uploads/lesions/dpn2.jpg).