PHENOLPHTHALEIN-INDUCED TOXIC EPIDERMAL NECROLYSIS

OBJECTIVE: To report a case of phenolphthalein-induced toxic epidermal necrolysis (TEN) in a patient maintained on several other medications more commonly known to be associated with TEN, CASE SUMMARY: A 78-yea r-old white man presented with intractable lower back pain and constip ation, On day 1 of admission, the patient exhibited a diffuse urticari al rash over his trunk and extremities. History revealed that the pati ent had taken a combination phenolphthalein/docusate sodium (Correctol ) over-the-counter laxative 1 day prior to admission. He had a similar urticarial rash 1.5 years earlier with this product and was instructe d not to use it, A biopsy was performed and evidence from light micros copic analysis of the tissue led to a diagnosis of TEN. Furosemide, sp ironolactone, allopurinol, and hydroxyurea were considered possible ca uses of the reaction and were discontinued. Despite this, the lesions worsened in severity, The patient subsequently responded well to intra venous antibiotics, intravenous corticosteroids, and local wound care. Furosemide, spironolactone, hydroxyurea, allopurinol, and docusate we re all reintroduced without reactivation of the lesions, DISCUSSION: P henolphthalein is the active ingredient in several over-the-counter la xative preparations and has only rarely been reported to cause TEN, (I t is no longer contained in Correctol,) To our knowledge, this case re port represents only the third description of laxative-induced TEN. Al though this patient had been exposed to several other medications more commonly associated with TEN, his long-term tolerance of and uneventf ul rechallenge with these medications exclude them as potential cataly sts to this drug reaction. The patient's previous rash and the tempora l relation of this event and the ingestion of phenolphthalein, as well as the similarity of this case to other reports, point to phenolphtha lein as the cause of TEN in this patient. CONCLUSIONS: TEN is a rare d isorder that can be fatal in up to 30% of patients. Clinicians should include phenolphthalein in their list of possible causes of drug-induc ed TEN, A careful and complete medication history can help avoid unnec essary discontinuation of clinically important medications and inadver tent rechallenge with the causative agent.