[Acute localized exanthematous pustulosis following heparin calcium injections]

Acute localized exanthematous pustulosis (ALEP) is a rare variant of acute generalized exanthematous pustulosis and is also defined by diagnostic criteria established by the EuroSCAR study group. Some twenty cases of ALEP have been described in the literature.

A 61-year-old woman suddenly developed erythematous and edematous lesions after subcutaneous heparin calcium injections in the thighs, with bullous detachment at the center of the lesions and multiple vesicles and non-follicular pustules on the edges. These lesions were centered around the injection points. There were no other skin lesions and no lesions on the oral mucosa, and the patient was apyrexial. The skin biopsy revealed an intracorneal pustule with spongiosis, as well as a prominent infiltrate of lymphocytes, neutrophils and eosinophils in the dermis, with no necrotic keratinocytes. We confirmed a definite diagnosis of ALEP, with a score of 10/12 according to the EuroSCAR criteria. A favorable outcome was quickly obtained after discontinuation of heparin injections, with only post-inflammatory pigmented macules.

This case shows that heparin calcium can lead to ALEP, thus contraindicating further administration of this substance. Other causative factors consist chiefly of systemic antibiotics, spider bites and exposure to certain plants. This case is remarkable in terms of the limitation of lesions to heparin calcium injection sites.