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BenignSkin of colourICD-10 L82

Dermatosis papulosa nigra

DPN; Castellani disease

Dermatosis papulosa nigra is a common, entirely benign condition of Fitzpatrick IV–VI adults — multiple small, dark-brown to black, hyperpigmented papules on the malar cheeks, forehead and lateral neck. It is biologically a variant of seborrhoeic keratosis with strong familial clustering, typically appearing in adolescence and progressing through adulthood. Diagnosis is clinical. Treatment is cosmetic only; ablative modalities are highly effective but carry a substantial risk of post-inflammatory dyschromia in darker skin, so gentle techniques and conservative test patches are essential.

CurrentLast reviewed 15 May 2026
Clinical image of Dermatosis papulosa nigra
Dermatosis papulosa nigra. Image sourced from DermNet New Zealand. Used under CC BY-NC-ND 4.0. No endorsement implied.

Clinical features

  • Multiple small (1–5 mm), dark-brown to black, smooth or slightly verrucous papules.
  • Distribution — malar cheeks, lateral forehead, temples, periorbital, lateral neck; less commonly upper chest and back.
  • Affects Fitzpatrick IV–VI predominantly; up to 35% of Black adults in the UK and US population studies.
  • Onset adolescence; numbers increase with age.
  • Strong familial clustering — often multiple affected relatives.
  • Asymptomatic.

Histology

  • Identical to seborrhoeic keratosis — acanthotic epidermis with horn cysts and hyperpigmentation of the basal layer.
  • Histology is rarely required for diagnosis.

Differential

  • Verruca plana (flat warts) — smaller, smoother, in groups, often on dorsal hands.
  • Acne / closed comedones — central white plug, periorbital and forehead.
  • Cherry angioma — bright red, vascular.
  • Acrochordon — pedunculated, neck.
  • Pigmented BCC — single, slow-growing, atypical.
  • Melanocytic naevi.

Management — and the dyschromia trap

  • Reassurance and no treatment is the default — the condition is benign.
  • Cosmetic options when patient requests:
    • Snip or scissor excision (small papules).
    • Light electrodesiccation or curettage.
    • Cryotherapy — use with caution; high risk of post-inflammatory hypopigmentation in darker skin.
    • Laser (KTP, pulsed dye, Er:YAG) — performed by clinicians experienced in skin of colour.
    • Topical retinoids — mixed evidence.
  • Always perform a test treatment on a single inconspicuous lesion before treating cosmetically prominent areas; counsel about the substantial risk of post-inflammatory hyper- or hypopigmentation.
  • UV photoprotection complements treatment to limit new lesion development.

References

  1. Castellani A. Dermatosis papulosa nigra. Original description; 1925.
  2. Niang SO et al. Dermatosis papulosa nigra in Dakar, Senegal. Int J Dermatol; 2007.
  3. Taylor SC et al. Dermatology for skin of color. 2nd edition. McGraw-Hill; 2016.

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