This paper describes a rare condition where patients develop painful red bumps on the shins (erythema nodosum) as a reaction to a severe scalp fungal infection (kerion) caused by Trichophyton mentagrophytes. The authors reviewed 23 similar cases and found that this reaction usually happens during antifungal treatment and resolves within about a week. Treatment with antifungal medications like griseofulvin, sometimes combined with anti-inflammatory steroids, is effective, though scarring of the scalp may remain.