IgE Penicillin V test detects serum IgE levels in patients sensitized with allergens of pencillium v, a clinically prescribed antibiotic used to treat infections. Oral or parenteral administration of the drug can cause either immediate or delayed mediated allergic reactions presenting with rhinitis, bronchospasm, urticaria, angioedema, anaphylaxis and maculopapular exanthematous skin rashes.