Treatment of focal idiopathic hyperhidrosis with Botulinum Toxin Type A: clinical predictive factors of relapse-free survival

Background No material about the identification of predictive clinical factors of therapeutic response to Botulinum Toxin Type A (BTX-A) in focal idiopathic hyperhidrosis has been found. Objective To evaluate if age, sex, extension rate of hyperhidrotic area, localization, disease-related impairment of life quality, number of previous local, non-invasive treatments different from BTX-A, and duration of disease, may affect the relapse-free survival (RFS) after a BTX-A treatment in palmar and axillary focal idiopathic hyperhidrosis. Methods Forty-one patients suffering from palmar hyperhidrosis, and 38 patients suffering from axillary hyperhidrosis received intradermal injections of BTX-A. All patients were clinically screened before and after treatment; they were followed for 15 months after it, according to Hyperhidrosis Disease Severity Scale (HDSS), Minor's test, and DLQI test, to state disease severity, and disease-related impairment of quality of life. Results The duration of therapeutic effect of BTX-A is not significantly influenced by age (P = 0.783), sex (P = 0.762), extension of hyperhidrotic area (P = 0.770), site of involvement (P = 0.402), disease-induced impairment of life quality (P = 0.745), number of previous therapies (P = 0.730), or site of involvement (P = 0.402). In palmar idiopathic hyperhidrosis, patients with a longer disease history show a shorter duration of RFS after a treatment with BTX-A (P = 0.01). Conclusions Patients suffering from palmar hyperhidrosis have a longer lasting disease, and a length of disease more than 20 years in these patients influences the RFS after BTX-A treatment.