diathesis (medicine) diathesis (medicine) in medicine and allied fields, diathesis (from greek διάθεσις) is a hereditary or constitutional predisposition to a group of diseases, an allergy, or other disorder. there are many types of diathesis. some including strumous diathesis, sthenic diathesis, and many more. atopic diathesis is a predisposition to develop one or more of hay fever, allergic rhinitis, bronchial asthma, or atopic dermatitis. types lupus diathesis strumous diathesis sthenic diathesis