A 25-year-old woman with newly diagnosed seizures comes to the emergency department with fever and skin rash. She had her first seizure 6 weeks ago, and an MRI of the brain revealed no structural lesions. She was started on phenytoin 4 weeks ago. Her temperature is 38.9 C (102 F). There is a diffuse confluent erythema involving 60% of the body, palpable generalized lymphadenopathy, and symmetrical facial swelling. Which of the following laboratory findings is most likely to be present in this patient?

Question

A 25-year-old woman with newly diagnosed seizures comes to the emergency department with fever and skin rash.  She had her first seizure 6 weeks ago, and an MRI of the brain revealed no structural lesions.  She was started on phenytoin 4 weeks ago.  Her temperature is 38.9 C (102 F).  There is a diffuse confluent erythema involving 60% of the body, palpable generalized lymphadenopathy, and symmetrical facial swelling.  Which of the following laboratory findings is most likely to be present in this patient?

Quizplus · Accepted Answer

This patient's cutaneous and systemic findings after recently starting a new medication suggest drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome. DRESS is a rare and potentially life-threatening drug reaction typically occurring 2-8 weeks after drug exposure. Commonly associated drugs include anticonvulsants (eg, phenytoin, carbamazepine), allopurinol, sulfonamides (eg, sulfasalazine), and antibiotics (eg, minocycline, vancomycin). Although the exact mechanism is unknown, it likely involves drug-induced herpesvirus reactivation followed by clonal expansion of T cells that cross-react with the drug. Patients typically develop fever, generalized lymphadenopathy, facial edema, and diffuse morbilliform skin rash that can progress to a confluent erythema with follicular accentuation. Other affected organs can include the liver (hepatomegaly, jaundice), kidney (acute interstitial nephritis), and lung (cough, dyspnea). Laboratory studies usually show eosinophilia, atypical lymphocytosis, and elevated serum alanine transaminase. Clinical findings improve over several weeks following withdrawal of the drug. (Choice A) Drug-induced antineutrophil cytoplasmic antibodies-associated vasculitis is most commonly linked to medications for hyperthyroidism (eg, propylthiouracil, methimazole) and hydralazine. Patients can develop constitutional symptoms, arthralgias/arthritis, and cutaneous vasculitis. (Choice B) Blast cells with Auer rods indicate acute myelogenous leukemia. Patients typically develop complications of pancytopenia, including fatigue (anemia), fever due to infection (neutropenia), and ecchymosis or epistaxis (thrombocytopenia). (Choice C) Mixed cryoglobulinemia is a small- to medium-vessel vasculitis caused by circulating immunoglobulin-complement complexes that precipitate on refrigeration. It is typically associated with chronic inflammatory states (eg, systemic lupus erythematosus, hepatitis C) and can present with systemic findings (eg, fatigue, arthralgias, myalgias) and palpable purpura in the lower extremities due to cutaneous vasculitis. (Choice E) Microangiopathic hemolytic anemia usually presents with anemia and fragmented red blood cells (schistocytes) on the peripheral smear. It has been associated with cancer chemotherapy drugs (eg, cisplatin, cyclophosphamide). Educational objective: Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome typically occurs 2-8 weeks after exposure to high-risk drugs such as anticonvulsants (eg, phenytoin, carbamazepine), allopurinol, sulfonamides (eg, sulfasalazine), and antibiotics (eg, minocycline, vancomycin). Patients typically develop fever, generalized lymphadenopathy, facial edema, diffuse skin rash, eosinophilia, and internal organ dysfunction. __________ 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 25-Year-Old Woman with Newly Diagnosed Seizures Comes to the Emergency