To the Editor: During my clinical study, "Allergic Rhinitis, a Common Cause of Recurrent Epistaxis,"1 one patient came to my attention with the unusual complaint of purple nosebleeds. Two other asthmatic children and one adult with bronchial asthma also complained of purple staining of their pillow cases. The adult asthmatic patient also noted that sneezing or coughing on a starched shirt left purple stains. Because this perplexing problem might recur, I thought it would be of value to record my observations and the probable explanation of this unusual phenomenon.
On further questioning it was noted that these 3 children and one adult were being treated with bronchodilator expectorant containing potassium iodide. The total daily amount of potassium iodide ranged from 0.6 to 0.9 gm. Potassium iodide excreted in the saliva or bronchial secretions, present in the blood of the epistaxis, or possibly still in the oral cavity produces the