Plantar warts are caused by a viral infection, while fossa keratosis is caused by a bacterial infection. The lesions of plantar warts are rounded papillary keratoses surrounded by a thickened keratin ring with a rough, spiny surface and can be asymptomatic.
Vulgar keratolytic lesions are superficial punctate keratotic pits that may fuse into irregular depressions or erosions, sweaty and foul-smelling. Treatment for plantar warts can include interferon therapy, immunomodulatory therapy, topical medication, intra-dermal injection of bleomycin, cryotherapy or laser therapy, photodynamic therapy, and surgical excision of warts, while treatment for fossa keratosis is mainly internal plus topical antibiotics such as erythromycin and clindamycin.