Improvement of Fox-Fordyce disease with botulinum toxin type A

Abstract

A 36-year-old patient with Fox-Fordyce disease (FFD) of bilateral axillary history of 4 years with pruritus. Topical treatments with 1% methylprednisolone aceponate, 0.5% tretinoin, and 1% clindamycin were prescribed, all with no response at 3 months. She also presented with hyperhidrosis, for which treatment with botulinum toxin type A, 75 units per side, was indicated. During follow-up, the patient showed a significant reduction in both sweating and the number of FFD papules. FFD is a rare, chronic disorder that affects areas rich in apocrine glands, mainly the axillae, anogenital, and periareolar regions. It is observed in young female patients. It presents as skin-colored papules, usually pruritic. It is caused by follicular plugging of the hair infundibulum in the distal portion of the apocrine duct and secretory portions of the apocrine glands. Secondarily, a local lymphohistiocytic inflammatory response occurs. Its cause is unknown, but a clear hormonal influence exists. Furthermore, cases have been described after laser hair removal.

Many treatments have been proposed based on isolated cases, but none have proven particularly effective. These include topical treatments: corticosteroids, calcineurin inhibitors, tretinoin, and clindamycin; systemic treatments: isotretinoin and oral contraceptives; and others such as laser, surgical excision, and phototherapy.

Regarding botulinum toxin, reducing sweating can relieve itching. Furthermore, there is clinical evidence of its antipruritic effect in other conditions such as lichen simplex chronicus, notalgia paresthetica, and brachyradial pruritus. The mechanism is related to the decreased release of acetylcholine, substance P, and glutamate, which are associated with itching. In contrast, the process by which botulinum toxin produces improvement in FFD is unknown. However, the authors suggest it as a valid therapeutic alternative for recalcitrant cases of FFD.