Clinical case of porphyria cutanea tarda

Cutaneous porphyria tarda is a rare skin disease characterized by a chronic course and the appearance of painful vesicular elements on the skin, localized mainly in open areas of the body under the influence of ultraviolet radiation. It is known that the development of porphyria in about a third of cases is familial and can also be associated with alcohol abuse, exposure to gasoline and other toxic substances, smoking, the presence of HIV infection, high iron levels in the body and liver damage with viral hepatitis C. A key link in the pathogenesis late cutaneous porphyria is considered a violation of the function of one of the enzymes in the liver cells involved in the synthesis of heme – uroporphyrinogen decarboxylase, which causes a violation of pigment metabolism with increased accumulation of porphyrins in the body, which are deposited in the skin and act as endogenous photosensitizers.

As an auxiliary tool for differential diagnosis in case of suspicion of late cutaneous porphyria, in addition to collecting a detailed anamnesis, it is necessary to clarify the presence of a pathognomonic symptom ― a change in the color of urine, since the accumulation of porphyrin in the body in some cases can change the color of urine to reddish-brown. Another tool is a skin biopsy, which usually helps with differential diagnosis.

In the treatment of late cutaneous porphyria, in addition to the treatment of viral hepatitis C, low doses of hydroxychloroquine are used. Although the disease is not completely curable, its course can be successfully controlled. In this regard, timely diagnosis of tardive cutaneous porphyria allows for control of the disease. The elimination and treatment of skin manifestations consists in the primary elimination of those factors that provoked the exacerbation of the disease. Such patients need to wear protective clothing, limit exposure to sunlight as much as possible, since to date there are no means that significantly reduce the level of porphyrin and restore the enzymatic insufficiency of uroporphyrinohendecarboxylase.

Molecular genetic testing is relevant in order to further reduce the risk of developing the disease in offspring, which requires limiting factors that reduce the levels and activity of uroporphyrinohendecarboxylase.

The search and development of effective drugs for the treatment of late cutaneous porphyria continues all over the world.

In the present paper we present a clinical case of cutaneous porphyria tarda associated with hepatitis C virus infection.