Derm Dx: Hand dermatitis with excess hair growth on the cheeks

Porphyria cutanea tarda is due to a deficiency of uroporphyrinogen decarboxylase, a hepatic enzyme involved in heme synthesis. It is the most common defect in heme synthesis with an estimated prevalence of 1 in 25,000 individuals in the United States.1The...

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Porphyria cutanea tarda is due to a deficiency of uroporphyrinogen decarboxylase, a hepatic enzyme involved in heme synthesis. It is the most common defect in heme synthesis with an estimated prevalence of 1 in 25,000 individuals in the United States.¹

The condition occurs equally in both men and women and can be inherited—or in the majority of cases—acquired. The genetic form typically presents in the fourth decade, whereas the sporadic form can present at any age.^2,3

Deficiency of uroporphyrinogen decarboxylase leads to the accumulation of porphyrins in the skin. Porphyrins absorb ultraviolet A and subsequently generate peroxidases that cause oxidative damage and cutaneous inflammation.

Patients with porphyria cutanea tarda present with findings of chronic blistering and delayed healing in sun-exposed areas, especially on the dorsal hands and forearms. Characteristic findings are vesicles, bullae, crusts, hypo and hyperpigmentation, and skin fragility. In addition, hirsutism and milia are often found on the cheeks and forearms.¹

Porphyria cutanea tarda is associated with hepatotoxic conditions such as chronic alcoholism, hemochromatosis, and hepatitis C.¹ Pregnancy and estrogen-based oral contraceptives may also induce this condition, as estrogen enhances iron storage.

Definitive diagnosis of this condition is accomplished by assaying a 24-hour urine sample, which will demonstrate abnormally high uroporphyrin levels.¹ Patients should be worked up for hepatic disease, including liver enzymes and viral hepatitis. Patients should also be instructed to eschew both ultraviolet light and alcohol, as avoidance of these factors can result in dramatic improvement.⁴

Phlebotomy is considered the treatment of choice for management of porphyria cutanea tarda.4 Phlebotomy leads to a reduction in iron stores and improved heme synthesis. Bloodletting is initially performed twice weekly with the goal of reducing serum ferritin levels to the lower limit of the reference range.⁵

An alternative therapy, used to treat milder disease or when phlebotomy is inconvenient or contraindicated, is use of low-dose antimalarials, either chloroquine or hydroxychloroquine.⁶

Megha D. Patel is a student at the Commonwealth Medical College, Scranton, Pennsylvania.

Stephen Schleicher, MD, is an associate professor of medicine at the Commonwealth Medical College and an adjunct assistant professor of dermatology at the University of Pennsylvania Medical College. He practices dermatology in Hazleton, Pennsylvania.

References

1. 1. Horner ME, Alikhan A, Tintle S, Tortorelli S, Davis DM, Hand JL. Cutaneous porphyrias part I: epidemiology, pathogenesis, presentation, diagnosis and histopathology. Int J Dermatol. 2013;52(12):1464-1480.
2. 2. Lambrecht RW, Thapar M, Bonkovsky HL. Genetic aspects of porphyria cutanea tarda. Semin Liver Dis. 2007;27(1):99-108.
3. 3.Aarsand AK, Boman H, Sandberg S. Familial and sporadic porphyria cutanea tarda: characterization and diagnostic strategies. Clin Chem. 2009;55(4):795-803.
4. 4. Tintle S, Alikhan A, Horner ME, Hand JL, Davis DM. Cutaneous porphyrias part II: treatment strategies. Int J Dermatol. 2014;53(1):3-24.
5. 5. Ratnaike S, Blake D, Campbell D, Cowen P, Varigos G. Plasma ferritin levels as a guide to the treatment of porphyria cutanea tarda by venesection. Australas J Dermatol. 1988;29(1):3-8.
6. 6. Singal AK, Kormos-Hallberg C, Lee C, et al. Low-dose hydroxychloroquine is as effective as phlebotomy in treatment of patients with porphyria cutanea tarda. Clin Gastroenterol Hepatol. 2012;10(12):1402-1409.