A 49-year-old man had a skin rash of three years' duration consisting of follicular pustules surrounded by areolae of purpura. He had had hepatosplenomegaly and suffers from arthralgia and purpura of the legs. His serum was shown to contain a cryoglobulin consisting of an IgG-IgM complex, with rheumatoid factor activity. Histologically, vasculitis was present around the pustules.
The syndrome of purpura, arthralgia, and mixed IgM-IgG cryoglobulinemia is one of a group of essential cryoglobulinemias due to circulating immune complexes, presumably causing damage at the sites of their precipitation.
The chronic follicular pustular purpura, which has not been described previously to our knowledge, is assumed to have evolved on the background of subclinical perifollicular vasculitis.
Nir MA, Pick AI, Schreibman S, Feuerman EJ. Mixed IgG-IgM Cryoglobulinemia With Follicular Pustular Purpura. Arch Dermatol. 1974;109(4):539-542. doi:10.1001/archderm.1974.01630040045010