Description

A rare chronic pruritic skin condition involving apocrine glands. Named for the physicians who first described it (1); also known as apocrine duct occlusion or apocrine miliaria; caused by destruction of follicular infundibulum with keratin debris

Epidemiology

Incidence
A rare condition without geographic, ethnic, or racial predilection. Approximately 90% of patients are women between the ages of 13 and 35 years. 10 times more common to occur in women than men. Incidence of the disorder is unknown.

Etiology and Pathophysiology

• A defect in the follicular infundibulum causes follicular dilation with keratin plugging. This results in apocrine duct obstruction, rupture, and inflammation (2,3), which causes extravasation of the apocrine secretions.
• Although blockage of the apocrine duct seems important in disease development, experimentally plugging the duct has not clinically reproduced disease manifestations.
• Unknown/possibly endocrine related

Genetics

• The genetics of Fox-Fordyce are unknown but likely play in role. There have been reports of the disease occurring in identical male twins, one set of siblings, in a father and daughter, in two patients with Turner syndrome, and in one patient with a small deletion on chromosome 21.
• Hormones
  • The role of hormones in Fox-Fordyce has been largely debated (1); disease onset after puberty and improvement with pregnancy and estrogens lends support to a hormonal influence.
  • However, hormonal studies in one patient with Fox-Fordyce did not reveal any abnormalities.

Commonly Associated Conditions

• Possibly related to hyperhidrosis
• Hidradenitis suppurativa (rare)