A 42-year-old woman comes to the emergency department with fever and a skin rash. She was diagnosed with trigeminal neuralgia and started on carbamazepine 3 weeks ago.
The patient's temperature is 38.9 C (102 F) . There is diffuse confluent erythema involving 60% of the body, palpable generalized lymphadenopathy, and symmetrical facial swelling. There are no mucosal lesions.
Her aspartate aminotransferase level is 150 U/L, eosinophil count is 800/mm³, and serum creatinine is 0.9 mg/dL.
Which of the following is the most likely diagnosis?

Question

Quizplus · Accepted Answer

This patient's fever and skin rash after starting a new medication suggest drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome. DRESS is a potentially life-threatening drug reaction typically occurring 2-8 weeks after initial exposure. Commonly associated drugs include anticonvulsants (eg, phenytoin, carbamazepine), allopurinol, sulfonamides (eg, sulfasalazine), and antibiotics (eg, minocycline, vancomycin). Patients typically develop fever, generalized lymphadenopathy, facial edema, and a diffuse morbilliform skin rash that can progress to a confluent erythema with follicular accentuation. The rash can involve the mucosa (eg, mouth, pharynx) but does not cause erosions. Other affected organs can include the liver (hepatomegaly, jaundice), kidney (acute interstitial nephritis), and lung (cough, dyspnea). Laboratory results show eosinophilia, atypical lymphocytosis, and elevated hepatic transaminases. Clinical findings usually improve with supportive care and stopping the drug, but resolution can take up to 6-9 weeks. skin rash (Choice A) Hypersensitivity vasculitis is characterized by fever, skin findings (palpable purpura, petechiae), arthralgias, lymphadenopathy, and elevated erythrocyte sedimentation rate. It is frequently associated with anticonvulsants, but there is usually no significant eosinophilia. (Choice C) Hypereosinophilic syndrome (HES) is characterized by profound eosinophilia (>1500/mm³) and multisystem involvement (eg, heart, gastrointestinal tract, lungs, brain, skin, kidneys) without an identifiable etiology. This patient's eosinophil count does not meet the criteria for HES. ³ (Choice D) Serum sickness-like syndrome can occur after exposure to drugs (often antiseizure drugs or antibiotics) or infections (eg, hepatitis B, Streptococcus) and causes systemic symptoms, arthralgias, and an urticarial or serpiginous macular rash. However, the reaction usually occurs within 1-2 weeks of drug exposure and does not cause significant eosinophilia. (Choice E) Stevens-Johnson syndrome is often triggered by exposure to new medications and is characterized by sudden-onset mucocutaneous lesions with subsequent necrosis and sloughing. However, mucosal involvement is usually prominent, and it does not cause eosinophilia or significantly elevated liver enzymes. Educational objective: Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome occurs 2-8 weeks after exposure to a new drug (eg, anticonvulsants, allopurinol, antibiotics). It is characterized by fever, lymphadenopathy, facial edema, diffuse morbilliform skin rash, eosinophilia, and elevated hepatic transaminases. __________ References: Drug reaction with eosinophilia and systemic symptoms (DRESS): an original multisystem adverse drug reaction. Results from the prospective RegiSCAR study. (http://www.ncbi.nlm.nih.gov/pubmed/23855313) The DRESS syndrome: a literature review. (http://www.ncbi.nlm.nih.gov/pubmed/21592453)

A 42-Year-Old Woman Comes to the Emergency Department with Fever