T-cell inducer populations in cutaneous inflammation: a predominance of T helper-inducer lymphocytes (THi) in the infiltrate of inflammatory dermatoses. The mononuclear infiltrate found in a variety of inflammatory dermatoses was characterized by a predominance of T helper-inducer lymphocytes (THi), CD4+/CD45RA-/CD45RO+, a population of cells responsible for maintaining and promoting immune reactions. Only small numbers of T-suppressor-inducer lymphocytes (TSi), CD4+/CD45RA+/CD45RO-, cells responsible for inducing CD8 suppressor-effector cells to 'down regulate' immune reactions, were seen. The predominance of CD4+ THi lymphocytes was common to all dermatoses studied and suggests a common final pathway in chronic cutaneous inflammation, irrespective of initial causative factors.