A 7-year-old girl is brought to the emergency department by her parents for generalized rash.  The mother reports that she was playing outside wearing a skirt and felt a sharp pain in her arm while seating on a mat, plying with her doll.  Her mother suspects that something had stung her.   The patient's blood pressure is 75/55 mm Hg and her heart rate is 122/min.  Physical examination shows erythematous, raised plaques over the trunk, extremities, and face.  Lung auscultation reveals bilateral expiratory wheezes.