Background: Botulinum toxin (Btx A) has recently been used in the treatment of focal hyperhidrosis. Hyperhidrosis is also an aggravating factor in nearly 40% of patients with dyshidrotic hand eczema. Objective: The objective of this study was to evaluate the effect of intradermal injections of Btx A on dermatitis in patients with vesicular hand dermatitis. Methods: Ten patients with vesicular dermatitis were treated on one hand with intradermal Btx A (mean, 162 U BOTOX, Allergan Pharmaceuticals, Irvine, Calif) with the untreated side as a control. Results: Self-assessment at follow-up 5 to 6 weeks after injection on a 5-point scale (none, slight, moderate, good, or very good effect) showed that 7 of 10 patients experienced good or very good effect. A decrease in itching was shown with a visual linear analogue scale (VAS) for itching, with mean 39% on the treated side compared with an increase by 52% on the untreated side. These findings were supported by the evaluation of clinical signs. Six of 7 patients who experienced good or very good effect also had aggravating hand sweating or worsening during the summer. Conclusion: Btx A can be a valuable alternative for patients with treatment-refractory hand eczema of the vesicular type, especially with hyperhidrosis or worsening during the summer. (J Am Acad Dermatol 2002;47:667-71.)