We present a healthy 35-year-old nurse with a history of urticaria from penicillin who suddenly developed polyarthralgias over a 3-month period. Since she could no longer jog, nor even climb one flight of stairs and had failed to respond to medications, she planned to take a medical leave of absence and move onto the first floor of her house. She had been seen by several rheumatologists who, after an extensive workup with blood tests and radiology exam, were unable to identify the etiology of this acute arthritis nor to find a medication which controlled her symptoms. She was emphatic that she had not taken any penicillin, nor related medications, prior to the onset of this event. She denied any hypersensitivities or significant changes in her lifestyle, exposures, or diet associated with this period aside from her family hosting a French exchange student for the last 4-months. After discussing the patient’s penicillin allergy with her, as well as the way penicillin was discovered, it was mentioned that penicillin is a common contaminant of any aging naturally rotting substance [2]. With this, she realized a potential source of her arthritis. To lessen the exchange student’s homesickness, she purchased aged cheeses for everyone to eat after school. With the acknowledgement that cheese is a natural source of penicillin, she changed her diet and within 2 weeks her polyarthralgias resolved [2].

The goal of this paper is to reinforce the idea that, especially in patients with atypical treatment resistant disease, there may be a hidden etiology which triggers the patient’s condition. The clue to such may include a history of an adverse cutaneous reaction. Although it is well recognized that many medications are derived from plant, animal, or mineral natural sources, what may not be considered is that reaction to medications also may indicate reactions to the food sources of these medications [3]. These reactions to the natural sources of medications may be more likely in patients who have had severe reactions to the medication, suggesting that a molar exposure lower than required for therapeutic effect can elicit an adverse immune response [4].