Current understanding of Baboon syndrome

Abstract

The term Baboon syndrome (BS) was introduced in 1984 to describe the characteristic development of diffuse bright red erythema on the gluteal and anogenital area – resembling the red rump of baboons as a particular clinical form of systemic allergic dermatitis. Additional symmetrical involvement of the upper inner thighs in a V-shaped pattern and major flexures occur frequently. Symmetrical flexural eczema in the absence of gluteal erythema would be better termed systemic allergic dermatitis, and not BS. Approximately 120 cases of BS have been reported to date. Systemic exposure to contact allergens (e.g., mercury) and systemic use of drugs usually without known prior cutaneous sensitization (e.g., amoxicillin) were the main causes. Ethical concern based on the comparison to an animal led to controversy as to whether to continue using the term or to avoid it completely. Such figurative allusions enable a first-glance diagnosis and reflect the terminological richness in dermatology. The acronym SDRIFE (symmetrical drug-related intertriginous and flexural exanthema) was recently proposed to replace BS in systemic drug-related cases. This is a comprehensive review of the previously documented findings in BS regarding its clinical features, histopathology and pathogenesis, with special focus on the causative agents and terminology. Furthermore, a subclassification of BS is proposed regarding both the causative agent and a demonstrable previous cutaneous sensitization: contact allergen-induced BS (excluding drugs), contact allergenic drug-induced BS and non-contact allergenic drug-induced BS.

Keywords::

• allergic contact dermatitis
• amoxicillin
• Baboon syndrome
• contact allergenic
• drug eruption
• hematogenous
• mercury
• patch test
• SDRIFE
• systemic contact dermatitis

Financial & competing interests disclosure

The author has no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.

Notes

^*Gluteal erythema is the main clinical feature of Baboon syndrome.

^‡Inguinal erythema appears in a characteristic V-shaped pattern on the upper inner thighs.

^§Systemic symptoms and signs are present only in rare cases.

Data from [1,5,6,17,201].

Data from [112,117,119,120].