Chapter 22: Dermatosis Papulosa Nigra

INTRODUCTION

Dermatosis papulosa nigra (DPN) is a condition where benign, darkly pigmented papules appear primarily on the face, neck, and trunk of women and men with skin of color worldwide.¹ DPN is often called pigmented papules, skin tags, or flesh moles. The incidence of DPN is reported to be as high as 70% in the African American population and up to 50% among family members of affected patients [Figure 22-1].^2,3

A retrospective study of 1000 Afro-Caribbean subjects ranked DPN as a common finding.⁴ In Africa, 40% of the population over the age of 30 has DPN.^1,5 Similar lesions have been described in Asians, Hispanic, and Latin Americans [Figure 22-2], although the exact incidence is unknown.^2,6,7

The development of DPN in children, although rare, has been reported.⁸ It is chronic and progressive in adults. Although DPN is generally asymptomatic, the papules can become pruritic and burning.⁹ Treatment is often pursued to enhance cosmetic appearance.

ETIOLOGY AND PATHOGENESIS

Castellani² reported the first case of DPN in 1925, but the exact etiology remains uncertain. It is speculated that DPN is derived from an epidermal nevus or a hamartoma with follicular origin or from a nevoid developmental defect of the pilosebaceous follicles.^10,11,12 The preponderance of DPN within certain families suggests a strong genetic predilection.¹¹ Niang et al¹³ suggest that the sun may be an etiopathogenic factor in the increase in lesions in the African population.

CLINICAL FINDINGS

DPN may begin as early as the first decade of life.⁸ However, these small, darkly pigmented papules usually begin in adolescence and progress slowly over the years, peaking in number in the sixth decade.¹¹ The average age of onset is 22 years.¹² DPN has been reported to have between a 1:1 and 2:1 female-to-male ratio of incidence.¹ Family history of DPN ...