[Acneiform eruptions induced by cetuximab.]

introduction. Many drugs may induce acneiform eruptions: vitamine B12, corticosteroids, androgens, lithium, tuberculostatics, halogens, some antidepressants, anticonvulsives and immunosuppressors. Many cases of acneiform eruptions can be observed following treatment with cetuximab, a drug used for solid cancers at advanced stages in experimental protocols. Case reports. Case 1. A 56 year-old woman, suffering from a colorectal cancer, developed a sudden acneiform eruption after 6 cures of cetuximab, at a one-week interval. She was treated with bisoprolol hemifumarate, sodium levothyroxin, cyproterone acetate and estradiol valerate. Clinical examination revealed inflammatory and follicular papulopustules localized on the face and upper chest. Comedos were absent. Itching sensations were discrete. Histopathological examination of a papulopustule revealed a folliculitis with polymorphonuclear neutrophils. PAS staining did not reveal the presence of bacteria or yeasts. Bacterial and fungal cultures were negative. Lesions faded in approximately 2 weeks following minocycline treatment (100 mg/day). Case 2. A 65 year-old man, treated by cetuximab for a colorectal adenocarcinoma, suddenly developped follicular inflammatory papulopustules on the face, trunk and extensor surfaces of both arms, after 3 weeks of treatment. Itching was discrete. Comedos were absent. Histopathology revealed the presence of a folliculitis with polymorphonuclear neutrophils. Bacteriology and mycology were negative. Lesions were partly controlled by administration of minocycline (100 mg/day) but worsened again in the days following each cure of cetuximab. Discussion. Cetuximab is a monoclonal antibody binding to the epidermal-growth-factor-receptor. It is used in the treatment of solid cancers at advanced stages. Both case reports share some similarities: the development of follicular inflammatory papulopustules distributed on the face and trunk typical, of acneiform drug eruptions. Itching is discrete. Comedos are absent. Quick onset of lesions is the rule. Cetuximab can be added to the list of drugs responsible for acneiform eruption.