Use of low‐dose naltrexone in the treatment of severe Hailey–Hailey disease: One case report

Hailey–Hailey disease (HHD) or chronic benign familial pemphigus is an autosomal dominant genodermatosis with complete penetrance characterized by painful vesicles, erosions, and macerated intertriginous skin. We present a 66‐year‐old woman with a personal 35‐year history of pruritic recurrent vesicles and erosions in both axillae and inguinal folds. HHD was confirmed by cutaneous biopsy. Past treatments had failed, including topical corticosteroids, antibiotics and oral doxycycline, minocycline, dapsone, and acitretin. Phototherapy and intralesional injection of toxin botulinum A was performed in the axillae. The patient was started on naltrexone 6.25 mg nightly. Six weeks later, complete clearing was observed. At typical doses, naltrexone blocks μ and δ opiod receptors, thereby blocking the union of β‐endorphins at those sites. Paradoxically, at low doses, the partial binding to those receptors leads to a homeostatic increase of opioid receptors and an upregulation of endogenous opioids. Low‐dose naltrexone (LDN) may also exert an anti‐inflammatory action through its antagonist effect on toll‐like receptor 4 found on macrophages. We consider that LDN is an effective and safe alternative for the HHD, representing an important progress in the management of this disease with limited therapeutic options.