Solar dermatitis in a cynomolgus macaque (Macaca fascicularis)

Area of Science:

• Veterinary Dermatology
• Primate Dermatology
• Environmental Dermatology

Background:

• Chronic ultraviolet (UV) light exposure is a known cause of skin damage, including actinic keratosis and dermatitis, in humans and animals.
• Actinic dermatosis is rarely reported in non-human primates (NHPs), making its presentation and management in this species under-documented.

Observation:

• A case of chronic UV light exposure in an adult female cynomolgus macaque (Macaca fascicularis) is presented, exhibiting multifocal alopecic, erythematous, and hyperkeratotic plaques with itching.
• Histopathological analysis revealed epidermal hyperplasia, hyperkeratosis, dermal fibrosis, and elastotic material deposition, consistent with solar dermatitis and elastosis.
• Two other macaques in the same enclosure developed similar dorsal skin lesions during the study period.

Findings:

• Systemic treatment with nutritional supplements and firocoxib did not improve the clinical signs of solar dermatitis.
• Concurrent topical therapy with aloe gel and a sunscreen spray (SPF50) halted the clinical progression of the skin lesions.
• The UV-induced skin damage in the cynomolgus macaque remained clinically stable under topical treatment.

Implications:

• This case highlights the susceptibility of cynomolgus macaques to UV-induced skin damage, emphasizing the importance of environmental management in captive primates.
• The findings suggest that topical photoprotection may be an effective strategy for managing solar dermatitis in non-human primates.
• Further research is warranted to understand the long-term effects and optimal treatment protocols for UV-induced dermatoses in NHPs.