It is difficult to recommend a precise follow up for the early diagnosis of new lesions. Approximately 40% of patients with one basal cell carcinoma will develop a second basal cell carcinoma within 5 years. Six percent of patients with one melanoma will develop a second melanoma. Patients with dysplastic nevi and a family history of melanoma have, without regular review, an almost certainty of developing melanoma in their lifetime. Significantly freckled individuals are at high risk for melanoma, as are those with nevi numbering more than 50.
All of these must be taken into account when recommending appropriate follow-up examinations. In general, if a patient has had a skin cancer or a pre-skin cancer, review by a physician once a year would be appropriate. In some individuals a pace of new lesions would suggest that a more frequent follow-up would be appropriate. Patients with multiple actinic keratoses are frequently seen at 3 to 4 monthly intervals with new lesions being treated at each visit.