Treatment of so-called idiopathic follicular mucinosis with hydroxychloroquine.

There exists no treatment of choice for follicular mucinosis (FM). Historically two distinct entities of FM have been proposed: FM of children and young adults not associated with other diseases ('idiopathic' FM), and FM in elderly patients associated with mycosis fungoides and Sézary syndrome ('lymphoma-associated' FM). Nowadays it is suggested that 'idiopathic' FM might represent a localized form of cutaneous T-cell lymphoma. Six patients with 'idiopathic' FM were treated with hydroxychloroquine (HCQ) at a dose of 200 mg three times daily for 10 days followed by a dose adjusted to the ideal body weight, usually 200 mg twice daily. All patients showed an improvement of 'idiopathic' FM already after 6 weeks and a complete remission with full hair regrowth after 2-5 months of HCQ therapy. In all patients no relapse occurred during follow up of between 3 and 23 years and no patient developed lymphoma. We conclude that HCQ is a highly effective therapy without significant side-effects in the treatment of so-called 'idiopathic' FM.