China: Case Study on Garlic Treatment and Koebner Phenomenon

In a recent case study published in the Journal of Cosmetic Dermatology, the researchers described the case of a 20-year-old female patient who developed a beaded rash following garlic treatment for facial wart plana, known as the Koebner phenomenon or autoinoculation.

Verruca plana is a benign skin proliferation caused by HPV (human papillomavirus) infection. Fresh garlic use can serve as an alternative therapy, and it is shown to have considerable effectiveness as a topical treatment for verruca plana. However, no previous reports of topical garlic treatment for the verruca plana-triggered Koebner phenomenon have existed.

The Koebner phenomenon (KP) is the development of previously normal skin lesions injured internally or externally. Verruca plana usually cause KP after the patient has scratched it. "To our knowledge, the case is the first to describe KP triggered by the garlic treatment for verruca plana," the researchers wrote.

Xinsuo Duan from the Affiliated Hospital of North China University of Science and Technology in Tangshan, Hebei Province, China, and colleagues explored the possible causes of this adverse reaction.

In the case described, topical garlic treatment for verruca plana triggered the Koebner phenomenon, primarily due to the operator's inadequate skill in applying garlic during the treatment.

"In addition to the need for individualized treatment regimens in terms of duration and frequency, it becomes important to apply the mashed garlic very precisely to warts," the team noted. "Garlic's direct contact with normal skin should be avoided."

The researchers suggest that before garlic treatment, patients undergo patch testing to identify any allergy to garlic. For allergic patients, garlic treatment is strictly prohibited, as the contact dermatitis caused by garlic may also trigger KP.

The main limitation of the paper is that this case cannot eliminate other possible causes that might have led to the increase of verruca plana, such as reinfection. However, based on the patient's medical history and clinical manifestations, the authors find it more convincing that garlic caused KP.

"Future research is needed to explore the underlying mechanism at molecular and cellular levels," they wrote.

The authors explained, "garlic may have caused damage to the surrounding normal skin through allergic reactions or primary irritation. Then, the HPV virus on the primary verruca plana took the opportunity to spread to the surrounding skin injured by garlic stimulation, triggering the KP."

"When using garlic for verruca plana treatment, the operator must precisely apply the mashed garlic to warts. This treatment is strictly prohibited for patients allergic to garlic," they concluded. "Avoid such adverse reactions."

Reference

Yu T, Che J, Song J, Duan X, Yang J. Topical garlic treatment for verruca plana triggers Koebner phenomenon: A case report. J Cosmet Dermatol. 2023 Mar;22(3):913-915. doi: 10.1111/jocd.15507. Epub 2022 Nov 14. PMID: 36374623.