Botulinum toxin type A in chronic non-dyshidrotic palmar eczema: A side-by-side comparative study.

New indications are being reported for intradermal botulinum toxin type A (BTX-A) owing to its anti-inflammatory and antipruritic actions. Its successful use for dyshidrotic hand eczema and lichen simplex has been reported in a few cases, while its utility in dry palmar eczema not associated with hyperhidrosis has not yet been investigated. The aim of this study was the assessment of the additive efficacy and tolerability of BTX-A in chronic dry palmar eczema. This prospective non-randomized side-by-side comparative study included 30 cases of chronic bilateral dry palmar eczema with no associated hyperhidrosis. Combined emollients and topical mid-potency steroid on one side were compared with an additive 100 units of intradermal BTX-A on the other side for efficacy and tolerability using both patient- and physician-oriented scores over a period of 6 months. Timing and extent of improvement and relapse were recorded on both sides, together with the frequency of development of side-effects. Both lines were effective and well tolerated, with significantly greater reduction of symptom and sign scores and higher overall patient satisfaction on the side receiving BTX-A, an effect which lasted for a significantly longer duration on this side (4 months) as compared with the other side (1 month). In conclusion, intradermal BTX-A at a dose of 100 units/palm is beneficial and well tolerated in chronic dry palmar eczema. Compared with topical steroid and emollients alone, its addition yielded superior efficacy that was longer lasting and more satisfactory to the patients, while exerting a steroid-sparing effect.