Management of Porphyria Cutanea Tarda
The standard of care for PCT consists of three core interventions: strict photoprotection, therapeutic phlebotomy to deplete hepatic iron stores, and low-dose antimalarial therapy (chloroquine or hydroxychloroquine), with phlebotomy being the first-line treatment in most cases. 1
Initial Assessment and Trigger Elimination
Before initiating specific therapy, identify and eliminate all exacerbating factors:
- Alcohol cessation is mandatory as it is one of the most common triggers for PCT 1, 2
- Discontinue estrogens, oral contraceptives, and hepatotoxic medications 1, 2
- Screen for and treat hepatitis C virus (HCV) infection if present, using direct-acting antivirals (DAAs) without interferon or ribavirin 1
- Test for hereditary hemochromatosis (HFE gene mutations), as this significantly influences treatment approach 2, 3
- Evaluate for diabetes mellitus, which is commonly associated with PCT 2, 3
Photoprotection (Immediate and Ongoing)
- Strict sun avoidance and physical sun protection are essential for all patients with active disease 1
- Use broad-spectrum sunscreens, protective clothing, and minimize sun exposure to prevent blistering and skin fragility 4
First-Line Treatment: Therapeutic Phlebotomy
Phlebotomy is the primary treatment modality for most PCT patients 1, 2:
- Perform regular phlebotomies (typically 450 mL every 1-2 weeks) until iron stores are depleted 1
- Monitor serum ferritin levels to guide treatment duration and assess iron depletion 1
- Continue phlebotomy until clinical remission occurs and urinary porphyrin levels normalize 3
- After remission, maintenance therapy may be needed based on ferritin levels 1
Phlebotomy is particularly preferred in patients with:
- Significant iron overload or hemochromatosis gene mutations 2, 3
- HCV-related liver disease, where chloroquine may be less effective 3
- Severe hepatic pathology 3
Alternative First-Line: Low-Dose Antimalarial Therapy
Low-dose chloroquine (125 mg twice weekly) or hydroxychloroquine is highly effective for porphyrin elimination 1, 2:
- This regimen is safe and avoids the hepatotoxicity seen with higher doses 2, 5
- Particularly useful when phlebotomy is contraindicated or poorly tolerated 1
- Effective as monotherapy in patients without significant iron overload 2
Important caveat: Chloroquine has limitations in patients with HFE gene mutations, where additional phlebotomy is typically required 2. It is also ineffective in chronic hemodialysis-associated PCT 2.
Treatment Monitoring
- Biochemical monitoring of urinary porphyrin levels should guide treatment duration 1
- Protect urine samples from light during collection and transport to avoid falsely low results 1
- Urine characteristically appears red to brown in natural light and pink to red under fluorescent light 4
- Monitor liver transaminases and blood glucose levels, which are often elevated 4
Management of Underlying Liver Disease
- Perform liver biopsy at presentation where possible to assess severity of hepatic pathology 3
- Patients with cirrhosis require regular screening for hepatocellular carcinoma 1
- Long-term monitoring is essential for patients with severe hepatic pathology or longstanding untreated PCT to detect hepatocellular carcinoma development 3
Special Populations
Chronic hemodialysis-associated PCT requires alternative approaches 2:
- Erythropoietin therapy
- Desferroxamine (iron chelation)
- Small-volume phlebotomy
Pediatric PCT (very rare) 2:
- Body weight-adapted chloroquine therapy
- Small-volume phlebotomy
Critical Avoidances
- Avoid iron supplementation and vitamin C supplements, as these can exacerbate the disease 1
- Do not use interferon or ribavirin-containing HCV regimens, as these can worsen or trigger new-onset PCT 6