Botulinum toxin type-A (BT-A) for the treatment of multiple eccrine hydrocystomas.

BACKGROUND The treatment of multiple eccrine hydrocystomas is challenging. Surgical excision is impractical. The outcomes of CO(2) and pulsed-dye laser therapy are not well studied. Botulinum toxin-A (BT-A) can block the secretions of the sweat glands and prevent dilatation of the cysts. OBJECTIVE To study the efficacy of BT-A on eccrine hydrocystoma. METHODS Eighteen patients with multiple facial eccrine hydrocystomas were treated by BT-A. The 500 IU vial of BT-A (Dysport; Ipsen Ltd, UK) was dissolved in 7.5 cc of normal saline to prepare a solution, 0.1 cc of which contains 6 IU of BT-A. Then, 0.1-0.2 ml of diluted BT-A was injected intradermally around the lesions using an insulin syringe with a 30-gauge needle. A second BT-A injection session was carried out 3-4 weeks later for four partially responsive patients. RESULTS Thirteen patients showed significant flattening of the lesions after the first session. The remaining partially responsive four patients showed considerable flattening after the second boosting session, performed 3-4 weeks later. The side effects were temporary and minimal. The duration of effect for the BT-A injection was 5-7 months. CONCLUSION Intradermal BT-A injection can be considered as a relatively safe and cost-effective treatment for multiple eccrine hydrocystomas.