Pretibial epidermolysis bullosa and hypothyroidism.

Background, We report a case of primary non-autoimmune hypothyroidism causi ng pretibial epidermolysis bullosa. Case report, A 70-year-old man with primary non-autoimmune hypothyroidism d eveloped blisters of different ages on the lateral aspect of both legs. Pat hology reported blisters with subepidermal cleavage. Direct immunofluoresce nce was negative. Electron microscope examination showed a variable cleavag e level and diffuse infiltration of a granulous and amorphous microfibrilla r substance. After hormone replacement therapy, euthyroidism was associated with a reduction in the number of bullae and finally complete remission. A fter 12 months follow-up, the patient has not experienced recurrence. Discussion, Recurrence-free clinical improvement after hormone replacement therapy suggests the diagnosis of hypothyroidism pretibial epidermolysis bu llosae. Mochizuki et al. described a similar case which rapidly regressed a fter hormone therapy but where the electron microscope showed a different c leavage level. These bullae appear to result from a mechanical mechanism du e to their localization in areas exposed to friction and also to the presen ce of bullae of different ages. This hypothesis is confirmed by the presenc e of a variable level of cleavage and a substance dense to electrons at ele ctron microscopy as well as by the skin weakness. Our case confirms the rea lity of hypothyroidism pretibial epidermolysis bullosa. Thyroid hormones sh ould be assayed in patients presenting pretibial bullae.