Hailey-Hailey disease treated with naltrexone: a question of dosage?

To the Editor: We read, with great interest, the studies by Kollman et al1 and Alajmi et al,2 which reported the efficacy of different dosages of low-dose naltrexone (LDN) in patients with Hailey-Hailey disease (HHD). Several studies have reported the efficacy of LDN in HHD over the past decade.1-4 There is no clear cutoff for LDN dosage, however. Interestingly, in Kollman et al,1 satisfactory 95% skin improvement was only achieved with 9-mg daily doses of naltrexone. Other studies have reported 2 patients successfully treated with 12.5 mg and 50 mg of naltrexone.