D3.37 - Beware of the Rare: AGEP

Background

Acute generalized exanthematous pustulosis (AGEP) is a rare condition, described as a delayed adverse drug reaction. It is charactarized by the formation of sterile pustules and frequent systemic involvement. Differential diagnosis can be challenging due to its clinical manifestations, often together with a history of simultaneous intake of several drugs, thus making the disease management a complex task.

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             Case Presentation

This is a case report of an 81-year-old Caucasian male who presented with a 4-day history of diffuse pruritic skin lesions with mucosal involvement and 1-day fever after 6-day treatment course with sulfamethoxazol/trimethoprim (SXT) for urogenital infection. The drug was suspended upon onset of symptoms, yet the skin lesions continued spreading and changing their morphology, together with general malaise. No concurrent therapy was reported, neither previous exposure to SXT. Written informed consent was obtained for collecting patient`s personal data and photos.

Physical examination and Workup

The alterations in local status comprised a diffuse erythemo-pustular exanthema; whitish plaques on the oral mucosa; geographic tongue; conjunctival hyperemia and periorbital edema. The patient was in a slightly impaired general condition, afebrile. Blood and urine tests results were inconclusive, except for elevated WCBs, neutrophils, hsCRP, ESR, IgE, fibrinogen.  SXT  has been already discontinued for 4 days. The treatment regimen included systemic corticosteroids, second-generation antihistamines, proton pump inhibitors and emollients. On Day 5 of hospitalization, a significant improvement of the clinical condition and laboratory parameters was observed, there were only isolated erythema and desquamation. 6 weeks later  SXT  patch test was performed with negative result. However, based on history, treatment with sulfonamides was contraindicated.

Discussion

Based on the morphological alterations and the disease course, the presented case is categorized as “probable AGEP” due to first SXT intake. The condition is a rare severe cutaneous drug reaction with estimated incidence between 1 and 5 cases per million per year. Discontinuation of the culprit agent, along with symptomatic therapy, contributed to the patient`s rapid recovery. Since AGEP has a tendency to relapse upon re-exposure, possibly with greater severety, and unpredictable complications, and prognosis, the suspension of the suspected agent is the current standard of care for such cases.