Erythematosquamous skin lesions in hereditary lactate dehydrogenase M-subunit deficiency

Peculiar erythematosquamous lesions were observed in two adult patients in Japan with hereditary lactate dehydrogenase M-subunit deficiency. Although these patients showed excessive fatigue and myoglobulinuria after extended exercise, they were usually asymptomatic. However, nonpruritic follicular papules or erythematous patches with scaly edges were present on the extensor surfaces of the extremities of these patients since childhood, showing some improvement after puberty. There were also erythematous patches on the weight-bearing areas of their soles. These patches showed exacerbation and a tendency toward peripheral spreading in summer. These skin lesions provide an important clue in the detection of this genetic enzyme deficiency.