E80.1 Porphyria cutanea tarda

Name of the Condition

• Porphyria Cutanea Tarda

Summary

Porphyria cutanea tarda (PCT) is a disorder of heme metabolism characterized by photosensitivity and skin fragility. It results from reduced activity of the enzyme uroporphyrinogen decarboxylase, leading to the accumulation of porphyrins in the liver and skin. Clinical manifestations primarily involve the skin, with symptoms triggered or exacerbated by sun exposure.

Causes

PCT is most commonly acquired and associated with factors that impair liver function or increase iron stores, such as chronic hepatitis C, excessive alcohol use, or estrogen therapy. Inherited (familial) forms involve mutations in the uroporphyrinogen decarboxylase gene, though symptoms typically require a triggering event to manifest. Environmental or lifestyle factors often contribute to disease onset.

Risk Factors

• Chronic liver disease (e.g., hepatitis C, cirrhosis).
• Excessive alcohol consumption.
• Iron overload (e.g., hemochromatosis, frequent blood transfusions).
• Estrogen use (e.g., oral contraceptives, hormone replacement therapy).
• HIV infection.
• Exposure to certain chemicals (e.g., hexachlorobenzene).

Symptoms

• Photosensitivity with skin blistering, particularly on sun-exposed areas (hands, forearms, face).
• Increased skin fragility, leading to erosions or bullae after minor trauma.
• Hyperpigmentation and skin thickening over time.
• Facial hypertrichosis (excessive hair growth) in some cases.
• Reddish-brown urine, which may darken upon standing.

Diagnosis

Diagnosis is based on clinical presentation, laboratory findings, and exclusion of other porphyrias. Key tests include measuring elevated porphyrin levels in urine (uroporphyrin and heptacarboxylporphyrin), serum ferritin, and liver function tests. A liver biopsy may show porphyrin accumulation. Genetic testing is reserved for familial cases or when other causes are unclear.

Treatment Options

• Phlebotomy to reduce iron stores (standard first-line therapy).
• Low-dose hydroxychloroquine to promote porphyrin excretion (used cautiously in liver disease).
• Avoidance of triggers (e.g., alcohol, estrogens, hepatotoxic agents).
• Management of underlying conditions (e.g., antiviral therapy for hepatitis C).
• Sun protection (sunscreen, protective clothing) to prevent skin damage.

Prognosis and Follow-Up

With treatment, skin symptoms often improve within months, but recurrence is possible if triggers persist. Long-term prognosis depends on controlling underlying liver disease and avoiding exacerbating factors. Regular monitoring of porphyrin levels, liver function, and iron stores is recommended. Most patients achieve remission with appropriate management.

Complications

• Chronic skin damage, scarring, or disfigurement.
• Increased risk of hepatocellular carcinoma in patients with underlying liver disease.
• Worsening liver function over time if triggers are unaddressed.
• Psychological impact due to visible skin changes.

Lifestyle & Prevention

• Strict sun avoidance and use of broad-spectrum sunscreen (SPF 50+).
• Limit alcohol intake or abstain entirely.
• Avoid estrogen-containing medications unless medically necessary.
• Maintain a healthy weight and manage iron intake (e.g., limit red meat, vitamin C supplements).
• Regular screening for liver disease or hepatitis if at risk.

When to Seek Professional Help

Seek care if you develop unexplained skin blistering, especially after sun exposure, or if you have risk factors (e.g., liver disease, alcohol use) and notice skin changes. Prompt evaluation is important to confirm diagnosis and initiate treatment, as untreated PCT can lead to progressive skin damage or liver complications.

Tips for Medical Coders

Document the clinical context, including triggers (e.g., alcohol, hepatitis C) or familial history, to support the diagnosis. Note the presence of photosensitivity, skin lesions, or laboratory confirmation of porphyrin elevation. Ensure documentation aligns with the acquired or familial nature of the condition, as this may impact coding specificity.