Overview
Variegated porphyrias, also known as South African-type hereditary porphyrias, mixed porphyrias, mixed hepatic porphyrias, and hereditary delayed porphyrias, have both a rash similar to that of delayed cutaneous porphyria (Porphyria Cutanea Tarda, PCT) and the neurologic and gastrointestinal symptoms of acute intermittent porphyria (AIP). The disease is autosomal dominant. The disease is inherited as an autosomal dominant disorder. Clinical manifestations are varied, with family members having either predominantly skin lesions, prominent neurologic or visceral lesions, or both, or the disease remaining latent for a long period of time. 2/3 of cases begin with a rash, more than 33% have skin lesions only, and about 15% have no skin lesions at all times. The onset of the disease is between 10 and 30 years of age, and the photosensitive rash is similar to PCT.
Etiology
The disease is inherited in an autosomal dominant pattern, with defects in protoporphyrinogen oxidase, increased fecal porphyrinogen and protoporphyrinogen, and increased uroporphyrinogen (PBG) in the acute phase.
Symptoms
The onset of the disease is between 10 and 30 years of age, and the photosensitive rash is similar to PCT. It does not often occur before adulthood, and when or shortly after sun exposure in summer, there is a burning sensation on the exposed parts of the face, neck, and the back of the hands, followed by erythema, edema, blisters, blisters, vesicles, vesicles, ulcers, and scabs, etc. The skin fragility is increased, and the face is purplish, with an increased number of blisters. Skin brittleness increases, the face is purplish and hairy, like Cushing’s syndrome face. Chronic cases show premature aging with a waxy, wilted complexion, increased forehead wrinkles, multiple shallow scars on the back of the collar and anterior hair margins, and scleroderma-like plaques and milia on the forehead and cheeks. In remission, there is hirsutism on the back of the hands and face, thin paper-like scarring on the back of the hands, small pearly scarring on the anterior hairline and hyperpigmentation. Acute exacerbations are characterized by neurologic and visceral lesions, and can also be induced by drugs, etc., similar to AIP.
Examination
Urinary porphyrin precursors are measured as in AIP. protoporphyrin III is increased in the feces during remission, and a mixture of equal parts of pentanol, glacial acetic acid, and ether is added to the feces and examined under an ultraviolet lamp, which shows pink fluorescence. Rubber finger cuffs after anal fingering also fluoresced under ultraviolet light. Fecal porphyrin III in the feces is increased in both the acute and remission phases.
Diagnosis
A definitive diagnosis can be made on the basis of symptoms and variable skin lesions during the acute exacerbation phase, along with laboratory tests. The disease should be differentiated from PCT by the similarity of skin rash manifestations. The latter has no acute attack symptoms, normal or slightly increased fecal porphyrins, and a predominance of fecal porphyrins.
Treatment
Avoidance of light and avoidance of drugs that can induce or exacerbate the disease is primarily symptomatic and is the same as for AIP and PCT. Glucose loading and hydroxyferrohemoglobin are of uncertain efficacy, and intravenous bloodletting and antimalarials are ineffective. β-carotene and zebra mussels may be effective in some patients.