Is vitiligo associated with wearing plastic shoes in a podoconiosis endemic region of Ethiopia?

Introduction: Endemic non-filarial elephantiasis also known as podoconiosis often affects bare footed farmers and is endemic in Ethiopia. The disease is prevented by wearing shoes. We recently observed several patients presenting to a dermatology clinic with skin depigmentation after wearing plastic shoes ("shoe-contact vitiligo") which may deter shoe-wearing. We report on their sociodemographic and clinical characteristics.

Methodology: This is a retrospective study of 17 months at tertiary level Hospital in Ethiopia. Patient data was retrieved from medical record department. We compared sociodemographic and clinical characteristics of patients presenting with idiopathic and shoe-contact vitiligo. Data was presented descriptively.

Results: Of 460 vitiligo cases, 190 (41%) were shoe-contact vitiligo and the rest, idiopathic. The former was more common in females (Odds Ratio, OR = 2.5, P < 0.001) and those in rural areas (OR = 4.8, P < 0.001). Fifty-five percent with shoe-contact vitiligo had itching and/or burning sensation, compared to just 2% with idiopathic vitiligo (P < 0.001) and some had ulcerations (8%). Idiopathic vitiligo had no such findings. Skin discoloration occurred within three weeks (on average) after wearing plastic shoes, 91% of lesions were symmetrical and involved areas of the feet covered with plastic shoes. Symmetric lesions were observed in only 11% of idiopathic vitiligo (OR = 81, P < 0.001).

Conclusions: Shoe-contact vitiligo was significantly associated with wearing cheap plastic shoes. The exact chemical culprit(s) needs to be identified. This will allow introducing quality control regulations and rigorous monitoring of shoe production sites.