Focal hyperhidrosis secondary to eccrine naevus successfully treated with botulinum toxin type A

Eccrine naevus (EN) is a rare skin hamartoma included in the organoid group of epidermal naevi, histologically defined as focal hyperplasia and/or hypertrophy of eccrine glands. Clinically, EN usually presents as hyperhidrotic patches with no visible skin changes, frequently located on the forearms. The decision to treat EN or not usually depends on the grade of hyperhidrosis, but there is no therapeutic consensus because of the rarity of this condition. We present a case diagnosed as EN in an adult patient with severe localized hyperhidrosis, which was successfully treated with botulinum toxin.