New topical photodynamic therapy for management of primary axillary hyperhidrosis: a single-blinded, placebo-controlled study

Background A variety of treatment modalities have been used in the management of primary axillary hyperhidrosis but no ideal treatment has been discovered yet. The recurrence and side effects of these modalities suggested the need for a long-acting treatment with a strong safety profile. Objective To study the efficacy and safety of photodynamic therapy in the management of primary axillary hyperhidrosis using topical eosin gel and intense pulsed light (IPL). Patients and methods Twenty patients were treated using IPL with a 400 nm filter, 20 ms pulse duration, and 25 J/cm2 fluence, once weekly, for four sessions after applying eosin gel to the right axilla for 1 h and placebo gel to the left. Efficacy was measured by the Hyperhidrosis Disease Severity Scale (HDSS), and assessment of sweating area reduction using the minor starch–iodine test. Liposomal eosin hydrogel has been prepared and applied on 24 rats to test for sensitivity reaction, and autopsies were examined histologically after irradiation of liposomal eosin hydrogel with light emitting diode. Results There was a highly significant reduction of the mean hyperhidrotic area from 65 ± 28.2 cm2 before treatment to 5.7 ± 5.2 cm2 at the end of treatment (P 0.01). A 90.1% reduction in the area of hyperhidrosis of the right axilla was obtained versus 2.2% reduction in the placebo site. A 3-point improvement on the 4-point (HDSS) was reported in seven patients (35%), a 2-point improvement was reported in nine patients (45%), and 1-point improvement was elicited in four patients (20%). Three patients (15%) reported a 1-point improvement from HDSS score 4 to score 3 at the placebo site. No recurrence occurred during the 8-month follow-up period. Conclusion Photodynamic therapy using eosin gel, which is photoactivated by IPL, is a noninvasive, safe, and effective method for management of primary axillary hyperhidrosis with no risk of multiple frequent injections and is not time-consuming. Further studies and long-term follow-up are needed.