History: Porokeratoses are seen in several forms.The disseminated actinic type is the commonest in white populations in sunny areas.The lesions rarely develope into squamous cell skin cancers.The linear type has the greatest risk of developing carcinoma.Treatment is often not indicated in this disseminated type because nothing works really well and creams such as efudix may cause unwarranted irritation with a low rate of success. Note the condition is inherited as an autosomal dominant disorder.