CBC with differential, reticulocyte and platelet count looking for eosinophilia and hemoconcentration. Urinalysis for protein, Chem Pannel, blood gases with respiratory distress. Differential Diagnosis - Drug rash . Pruritic macular or maculopapular rash over trunk and extremities may progress to serum sickness. History of exposure to a drug usually started in the past 7 to 10 days for first exposure or 12 to 72 hours with re-exposure.
Many drugs have more characteristic presentation or photoactivation.
Eosinophilia is common. All narcotics, especially morphine, may stimulate histamine release. This can cause itching, urticaria, and broncospasm in patients with reactive airway disease. Localized maculopapular, vesicular or pustular rash. May be under jewelry with nickel sensitivity, on face, eyes, or ears with cosmetic sensitivity, or linear with poison ivy, oak, or summac.