A rare, itchy, chronic papular eruption localized to apocrine gland–bearing areas of the body with unclear etiology.
Females are disproportionately affected compared to males (9:1), with age of onset most commonly between 13-35 years of age.
Hyperkeratotic plugging of the follicular infundibulum at the apocrine gland duct insertion site is thought to be the primary pathophysiologic event, leading to duct dilation, rupture, inflammation, and pruritus.
No definitive cure; oral antihistamines and topical clindamycin may help alleviate symptoms and induce remission.
Fox-Fordyce disease is a chronic, itchy, papular eruption involving apocrine gland–rich areas of the body. Lesions are characterized by numerous firm, flesh-colored, follicular-based papules arranged in a grouped configuration.1 Fox-Fordyce disease was first described in 1902 by George Henry Fox and John Addison Fordyce in 2 patients with axillary disease.2 The pubic, perineal, areolar, umbilicus, and sternal areas also can be involved.3,4 Fox-Fordyce disease is otherwise known as apocrine miliaria; however, the centrality of apocrine gland dysfunction to the disease pathophysiology remains controversial.1,5
The incidence of Fox-Fordyce disease is unknown; however, it is considered a rare disease. Epidemiologic studies suggest Fox-Fordyce disease disproportionately affects females.3,6 Females between the ages of 13 and 35 years comprise more than 90% of cases. Fox-Fordyce disease is rarely reported before puberty or after menopause.7 There is no known racial predilection for the disease.
Fox-Fordyce disease typically manifests after the onset of puberty, most commonly in the axillae. Patients may notice lesions for the first time with shaving.8 Diagnosis is often delayed for years,9-11 as the eruptions may only itch initially with onset12 or not at all.11 The number of lesions accumulate slowly over time.13 Pruritus is intermittent and intense. Itchiness is made worse by sympathetic stimulation, including sweating, emotional stress or excitement, and warm weather.13 Family history is usually unremarkable.
Fox-Fordyce lesions manifest as grouped, symmetrically distributed, monomorphic, dome-shaped papules (1 to 3 mm) that are typically follicular based, flesh-colored to mildly erythematous, and intermittently pruritic (Figs. 83-1 and 83-2). Excoriations and lichenification are often present secondary to scratching. The axillae are most commonly affected. The pubic, perineal, areolar, umbilicus, and sternal areas also can be involved. Diminished sweat production is frequently observed in affected areas.11
Fox-Fordyce disease with skin-colored papules involving the axilla. (Image used with permission from the Graham Library of Wake Forest Department of Dermatology.)
Fox-Fordyce in a dark-skin patient with well-demarcated papules on the axilla. (Image used with permission from the Graham Library of Wake Forest Department of Dermatology.)