Equestrian chilblain: another outdoor recreational hazard.

This study revolves around the examination of two unique cases and a review of 14 documented cases of equestrian chilblain or ‘equestrian cold panniculitis’. The aim is to understand the symptoms, obtain comprehensive histopathologic findings, and explore its relation to other cold-induced skin injuries and autoimmune connective tissue diseases, specifically lupus erythematosus.

Initial Overview of Cases

• Case 1 includes a 23-year-old female horse trainer who exhibited symptoms of burning nodular swelling on her lateral thighs.
• Case 2 highlights a 34-year-old woman who experienced recurring nodular eruptions on her lateral thighs after horse riding in the winter.
• Physical examinations showed changes in skin color and texture, with both patients having erythematous to violaceous nodules with changes resembling eczema craquelé.
• Tests to identify systemic and autoimmune connective tissue diseases in both patients were negative.

Biopsy and Histopathologic Findings

• Biopsy samples from both patients were taken via punch method, wherein tissue was harvested for testing.
• The biopsy results displayed a superficial and profound perivascular and periadnexal lymphocytic infiltrate with focal reaching into the subcutaneous fat.
• The presence of parakeratosis, subtle spongiosis, and an increase in pandermal interstitial mucin were also observed.
• A distinguishing feature was the increased pandermal interstitial mucin resembling tumid lupus erythematosus, a variability from typical histopathologic findings of equestrian chilblain.

Comparative Analysis with Other Cases

• Upon reviewing 14 other documented cases, the researchers found that the clinical course and histopathologic findings were largely similar to the two cases in the study.
• The researchers focused on the increased presence of pandermal interstitial mucin, a feature that echoes symptoms akin to tumid lupus erythematosus, a variant of lupus, which led them to further scrutinize the relationship between equestrian chilblain and autoimmune connective tissue diseases.

Aim and Conclusion

• The researchers’ aim was to provide a more detailed characterization of the histopathologic findings of equestrian chilblain and expand their understanding of its relation to cold-induced skin injuries and autoimmune connective tissue diseases.
• The study leads to a more profound comprehension of the symptoms, causes, and potential relationships of equestrian chilblain, providing a foundation for future in-depth studies.