CPOX

Hereditary coproporphyria (HCP)

AD

Blistering skin lesions closely resembling lesions of CEP

HCP, an acute hepatic porphyria, is generally accompanied by neurovisceral features, esp bouts of severe abdominal pain, which are not observed in HEP. Development of blistering skin disease is uncommon in HCP, whereas it is present severe in HEP. Mild manifestations of HEP can be mistaken for HCP.

PPOX

Variegate porphyria (VP)

AD

Blistering skin lesions are nearly identical to those in HEP. Cutaneous manifestations in HEP are chronic blistering (like in VP) but are usually more severe than those of VP, because circulating porphyrin levels in HEP are usually much higher than in VP.

VP is a cutaneous acute porphyria can present w/cutaneous manifestations /or acute attacks of neurovisceral manifestations similar to AIP.; Plasma porphyrin fluorescence scanning of diluted plasma at neutral pH w/peak wavelength ~626 nm is seen w/VP. This is very useful in differential diagnosis.

UROD

Familial porphyria cutanea tarda (F-PCT)

AD

Skin lesions resemble those of HEP but are less severe typically begin later, in the 5th or 6th decade of life.

Because laboratory findings in F-PCT HEP can be clinically indistinguishable at time of diagnosis, molecular genetic testing is necessary to discriminate between these disorders. Measurement of UROD enzyme activity is not an accurate method to distinguish between F-PCT HEP. UROS

GATA1

Congenital erythropoietic porphyria (CEP)

ARXL1

The skin lesions of CEP, like those seen in HEP, appear early in life (i.e., in infancy or childhood) are severe mutilating.

In both CEP (a cutaneous, erythropoietic porphyria) HEP, severity is attributed to plasma concentration of porphyrin. Although CEP can be mistaken for HEP, urine porphyrin analysis (which shows marked in uroporphyrin coproporphyrin type I in CEP) helps exclude other cutaneous porphyrias.