All of the following are primary cutaneous disorder except-
Reiter's syndrome is a multisystem disease characterized classically as a triad of nongonococcal urethritis, conjunctivitis, and ahritis in association with the mucocutaneous lesions of keratoderma blenorrhagica and balanitis circinata. it is reactive pattern of disease after an episode of infection presenting as cervicitis ,urethritis and gastroenteritis iadvl textbook of dermatology page 1861
Psoriasis
Reiter's disease
Lichen planus
Icthiosis
miscellaneous