Demonstration of deficient uroporphyrinogen cosynthase activity confirms the diagnosis. ALA and PBG are not increased. Hepatoerythropoietic porphyria is similar clinically, but porphyrin patterns are different. Treatments for CEP are not very effective. Therefore, avoiding sunlight and wearing protective clothing are important.
Several manufacturers specialize in protective fabrics and clothing for sun-sensitive people.
More recently NASA has developed a special space suit for CEP patients to wear. Heterozygotes can be detected in affected families, and diagnosis in utero is possible. Therefore, there are options for preventing genetic transmission.