Hereditary lactate dehydrogenase M-subunit deficiency with late-developing pustular psoriasis-like lesions.

Hereditary lactate dehydrogenase (LDH) M-subunit deficiency is very rare and we have found reports of close to a dozen cases in the published work, two of which were associated with pustular psoriasis-like lesions. We report a third case of pustular psoriasis-like eruptions associated with LDH M-subunit deficiency, which occurred 24 years after the diagnosis of LDH M-subunit deficiency. These cases indicate that abnormal activity of LDH can induce pustular psoriatic lesions in the long term. Some patients with symptoms of hereditary LDH M-subunit deficiency have antecedent annular scaly plaque lesions, that resemble psoriatic lesions. We discuss a hypothesis to explain this scenario.