Case reports 6 patients, aged from 33 to 77 years old, presented with a variable 4 to 40 year history of severe treatment-resistant HHD. All 6 patients were then treated successfully with doxycycline 100 mg per day for at least 3 months.
Discussion An improvement was observed in all 6 patients from 1 week to 3 months after the beginning of treatment. Relapses were observed after various periods. Maintenance half-dose therapy seemed to be beneficial in patients experiencing recurrence. Only one patient developed gastro-intestinal intolerance. No other side effects were reported. Currently, 2 patients have improved and present a decreased number of exacerbations, 2 others are in complete remission after more than 5 years of follow-up. Treatment efficiency is difficult to evaluate in HHD as it is a rare condition. No controlled studies have been published. Local treatments may improve inflammation but do not treat the underlying cause, targeted systemic therapies exist but there is little evidence supporting their use, physical treatments are cumbersome. Besides their antibiotic potential, tetracycline antibiotics also have anti-inflammatory properties and anticollagenase activity via inhibition of matrix metalloproteinases.
Conclusions Doxycycline appears to be an interesting therapeutic option in Hailey-Hailey disease.