The course and development of atopic symptoms were followed up in 801 atopic dermatitis patients, in 207 allergic rhinitis or asthma patients, and in 517 control subjects. The patients were studied in the Dermatology Clinic during their teens and the follow-up studies were carried out at the ages of 22-41. Persistent or frequently relapsing dermatitis occurred in 77-91% of those who suffered from severe or moderate atopic dermatitis during their teens and in more than one half of those patients who only had mild dermatitis at the corresponding age. Atopic dermatitis had started in 13-17% of allergic rhinitis/asthma patients. At the time of the follow-up examination, severe dermatitis was seen in only six percent and moderate symptoms in 35% of atopic dermatitis patients. Dermatitis was generally seen in multiple loci: on the face, hands, extremities, and body. Deterioration of dermatitis in autumn and winter was experienced by one third to 88% of the atopic dermatitis patients. Psychic stress was experienced as a major aggravating factor in one half to two thirds of atopic dermatitis patients. Prick test positivity occurred in 62-89% of the dermatitis patients. Animal allergens, molds, grasses, birch, and house dust mite were the most common allergens. Associations between evident allergen exposure and deterioration of the dermatitis occurred in individual cases.