Linear IgM dermatosis of pregnancy

An intensely pruritic dermatosis that occurred in a woman during the third trimester of pregnancy is described. The clinical manifestations included red follicular papules symmetrically distributed on the skin of the forearms, abdomen, thighs, and legs. The histopathologic findings were not specific. However, immunopathologic examination revealed dense linear deposition of IgM in the dermoepidermal junction. The eruption and the immunopathologic findings disappeared at the end of the puerperium. This dermatosis differs from previously described specific dermatoses of pregnancy because of the clinical appearance and the immunopathologic findings. Thus we propose the term linear IgM dermatosis of pregnancy.