Using test dose challenges to restore essential therapy in patients with idiopathic anaphylaxis and pharmacophobia: report of a patient with idiopathic anaphylaxis and statin phobia.

Idiopathic anaphylaxis (IA) is a well-documented condition in which anaphylaxis occurs in the absence of an identifiable precipitant. However, many patients with IA find it difficult to accept this diagnosis and continue to search for an external cause. It is not uncommon for these highly anxious patients to discontinue essential medications that they feel are responsible for the reaction despite reassurance from their physicians to the contrary. In extreme cases, these patients may develop an actual phobia to preexisting medications and avoid them despite adverse consequences to their health. To illustrate this concept, we report a case involving a female patient with familial hypercholesterolemia who experienced a single episode of IA and developed a "statin phobia," falsely implicating her medication (lovastatin) for the reaction. After 5 years of failed therapy with other antihyperlipidemic agents, the patient finally agreed to undergo test dosing to a similar statin agent atorvastatin. On successful completion of the test, she resumed therapy with atorvastatin and her low-density lipoprotein (LDL) levels were reduced by 50% over 5 months. We conclude that patients with a confirmed diagnosis of IA who manifest phobic responses to beneficial medications should be reassured of the diagnosis promptly by their physician. When reassurance fails and the medication is essential to the patient's health, test dose challenges may be conducted to reintroduce the drug to the patient's regimen.