D3.42 - Symmetrical drug-related intertriginous and flexural exanthema related to symptomatic slow-acting drug for osteoarthritis (SYSADOA) – a case report

Background:

Symmetrical drug-related intertriginous and flexural exanthema (SDRIFE) often times referred to as “baboon syndrome” is a rare benign cutaneous drug-eruption characterized by symmetrical dermatitis in the intertriginous areas of the body. SDRIFE is associated with systemic drug intake. Although antibiotics in particular penicillins account for around 50% of cases, many other drugs are also reported to have such an adverse drug reaction.

Case Report:

A 56-year-old female patient presenting with a pruritic, macular erythematous rash with zones of desquamation. The skin lesions affect symmetrically the lower quadrants of the abdomen, gluteal area, infragluteal fold and the knees. The eruption began 2 weeks after starting a second course (lasting for about 3 months) of a symptomatic slow-acting drug for osteoarthritis (SYSADOA) – with ingredients consisting of an unsaponifiable fraction of avocado oil and soy bean oil. No relevant medical history was present. Laboratory results revealed ANA-screening 1:320, all other results were within normal ranges. Dermatology consult was performed, with suspicion of SDRIFE, as no other possible causes for contact dermatitis were identified. Treatment included systemic corticosteroids and subsequently topical steroids, and emollients with noticeable improvement within 1 week. 

Follow-up of the patient was performed after 5 months. Patch testing (European baseline series and suspected drug in petrolatum) was performed: negative for SYSADOA, and positive results for textile dye, and fragrance mix. Although drug provocation testing is considered the most valuable diagnostic method, the patient did not consent further investigation. There were no subsequent administrations of the suspected drug, nor have there been any additional skin lesions. 

Discussion:

SDRIFE is characterized by symmetrical erythema, typically affecting gluteal, inguinal, flexural areas. Although no SYSADOA drugs were reported for causing such reactions, the typical localization and lack of systemic involvement points towards the possible diagnosis of SDRIFE. Drug provocation testing is considered the diagnostic gold standard, though oftentimes patients are hesitant to undergo further investigation, due to the risk of recurrence of symptoms.