Are You Confident of the Diagnosis?
Characteristic findings on physical examination
Dermatosis papulosa nigra is found in black people. It is assumed that dermatosis papulosa nigra in fact is a variant of seborrheic keratosis in darkly pigmented people. The lesions occur usually as multiple black papules with a diameter of 1 to 5mm. They are preferentially located on the face, neck, upper back and chest. The lesions resemble tiny pigmented seborrheic keratoses. The clinical appearance is very typical and in most cases the diagnosis can be made without difficulty (Figure 1).
Expected results of diagnostic studies
Differential diagnosis includes other benign skin tumors such as melanocytic nevi, adenoma sebaceum (if the lesions are arranged along the nasolabial folds) and trichoepitheliomas. In doubtful cases, histopathologic diagnosis will be helpful. Dermatosis papulosa nigra is characterized by acanthosis, moderate papillomatosis and hyperkeratosis. The histologic picture is identical with acanthotic seborrheic keratosis, with the exception that horn pseudocysts are less common in dermatosis papulosa nigra.
Who is at Risk for Developing this Disease?
Dermatosis papulosa nigra is commonly found in black people. Occurrence in Asians and Mexicans has been reported as well. The prevalence of dermatosis papulosa nigra in black people was 77% in one study. This study found also a preponderance of females with a male:female ratio of 1:2. Dermatosis papulosa nigra is absent in childhood, but usually develops earlier in life than seborrheic keratoses. The number of lesions increases with age.
What is the Cause of the Disease?
The etiology of dermatosis papulosa nigra remains elusive. A genetic predisposition may play a role because many patients report a positive family history. Recently, FGFR3 mutations have been identified in dermatosis papulosa nigra. These mutations have been previously reported in seborrheic keratoses. The detection of FGFR3 mutations in dermatosis papulosa nigra further supports the concept that this lesion is indeed merely a variant of (acanthotic) seborrheic keratosis in darkly pigmented people.
Systemic Implications and Complications
Analogous to seborrheic keratosis, dermatosis papulosa nigra is a benign skin tumor without malignant potential. Because of the occasionally high number of lesions and the localization in visible areas, dermatosis papulosa nigra may be cosmetically disturbing and the patients will therefore wish to remove the multiple lesions.
Optimal Therapeutic Approach for this Disease
It has to be considered that treatment is not necessary due to the benign character of dermatosis papulosa nigra and will only be for cosmetic reasons. Various methods can be used for removal such as shave excision, curettage, cryotherapy, electrodesiccation or (ablative) lasers. Pulsed dye laser did not show a better result than curettage or electrodesiccation. Precaution is recommended for all therapies because of a relevant risk of postinflammatory hypo- or hyperpigmentation in darkly pigmented individuals.
Patient reassurance that these lesions are benign and are of no significance other than cosmetic appearance is essential. Treatment is only necessary should the patient desire it or, on the rare occasion, when lesions become irritated.
Unusual Clinical Scenarios to Consider in Patient Management
What is the Evidence?
Ali, FR, Bakkour, W, Ferguson, JE, Madan, V. “Carbon dioxide laser ablation of dermatosis papulosa nigra: high satisfaction and few complications in patients with pigmented skin”. Lasers Med Sci. 2016 Feb 11. (This is a retrospective case review from one center)
Grimes, PE, Arora, S, Minus, HR, Kenney, JA. “Dermatosis papulosa nigra”. Cutis. vol. 92. 1983. pp. 32-385-6. (This study has analyzed the prevalence of dermatosis papulosa nigra among darkly pigmented people.)
Hafner, C, Landthaler, M, Mentzel, T, Vogt, T. “FGFR3 and PIK3CA mutations in stucco keratosis and dermatosis papulosa nigra”. Br J Dermatol. vol. 162. 2010. pp. 508-12. (This study identified FGFR3 mutations in dermatosis papulosa nigra, supporting a relationship with seborrheic keratosis.)
Hafner, C, Toll, A, Fernandez-Casado, A, Earl, J, Marques, M, Acquadro, F. “Multiple oncogenic mutations and clonal relationship in spatially distinct benign human epidermal tumors”. Proc Natl Acad Sci U S A. vol. 107. 2010. pp. 20780-5. (This study shows that multiple oncogenic mutations (FGFR3, PIK3CA, RAS) are present in benign seborrheic keratoses, although these lesions lack a malignant potential.)
Garcia, MS, Azari, R, Eisen, DB. “Treatment of dermatosis papulosa nigra in 10 patients: a comparison trial of electrodesiccation, pulsed dye laser, and curettage”. Dermatol Surg. vol. 36. 2010. pp. 1968-72. (This study compared pulsed dye laser with electrodesiccation and curettage for removal of dermatosis papulosa nigra but found no advantage for the laser treatment.)
**The original source for this chapter was Dr. Christian Hafner. The chapter was revised for this program by Dr. Michael Gober.**
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- Are You Confident of the Diagnosis?
- Who is at Risk for Developing this Disease?
- What is the Cause of the Disease?
- Systemic Implications and Complications
- Treatment Options
- Optimal Therapeutic Approach for this Disease
- Patient Management
- Unusual Clinical Scenarios to Consider in Patient Management
- What is the Evidence?