Exacerbation of erythropoietic protoporphyria by hyperthyroidism

Area of Science:

• Hepatology
• Endocrinology
• Genetics

Background:

• Erythropoietic protoporphyria (EPP) is a rare genetic disorder affecting heme synthesis, primarily causing photosensitivity and potentially severe liver damage.
• Liver complications in EPP, though rare (<5%), represent a serious clinical challenge.
• The interplay between EPP and other autoimmune or endocrine disorders remains largely unexplored.

Observation:

• A patient with EPP presented with worsening skin symptoms, nervousness, and insomnia, alongside elevated liver enzymes and erythrocyte protoporphyrin levels.
• Diagnostic workup revealed concurrent Graves' disease, indicated by suppressed TSH and elevated thyroid hormones (FT3, FT4) with positive autoantibodies (TPOAb, TRAb).

Findings:

• Radioiodine therapy for Graves' disease led to significant reduction in thyroid volume and normalization of liver enzymes.
• Following treatment, erythrocyte protoporphyrin levels decreased fivefold, and the patient's cutaneous symptoms and insomnia markedly improved.
• This case, one of only two reported, highlights a rare coexistence of Graves' disease and EPP.

Implications:

• The findings suggest a potential, albeit rare, interaction between Graves' disease and EPP, particularly in patients with liver involvement.
• Screening for thyroid dysfunction, specifically hyperthyroidism, is recommended in EPP patients presenting with liver complications.
• Further research is warranted to elucidate the underlying mechanisms connecting Graves' disease and EPP pathophysiology.