<prompt> Keratitis is caused byBacteriaAtopyProtozoaAll  <response>: Causes of keratitis Infective keratitisBacterialViralFungalChlamydialProtozoalSpirochactal Allergic keratitisPhlyctenular keratitisVernal keratitisAtopic keratitis Trophic keratitisExposure keratitisNeuroparalytic keratitisKeratomalaciaAtheromatous ulcer Keratitis associated with diseases of skin and mucous membrane.Keratitis associated with systemic collagen vascular disorders.Traumatic keratitis, which may be due to mechanical trauma, chemical trauma, thermal burns, radiations. Idiopathic keratitis e.g.,Moorens corneal ulcerSuperior limbic keratoconjunctivitisSuperficial punctate keratitis of Thygeson 