Analysis: Estrogen Therapy Linked to Twofold Higher Odds of Porphyria Cutanea Tarda
Key Takeaways
Estrogen-containing therapy was associated with approximately twice the odds of incident porphyria cutanea tarda (PCT) in a nationwide Danish case-control study involving 44,238 women.
Estrogen-containing contraceptives, estrogen-only therapy, and combined estrogen-progestogen therapy were each associated with increased odds of PCT.
Oral estrogen therapy was associated with PCT (adjusted OR, 2.44), whereas nonoral administration was not, identifying a potential distinction by route of administration.
New research published in JAMA Dermatology finds an association between estrogen-containing therapies and porphyria cutanea tarda, with differences observed by administration route.
Researchers on the study examined whether estrogen exposure was associated with new PCT diagnoses across different hormonal formulations and routes of administration. Previous evidence identifying estrogen as a potential PCT risk factor had largely come from clinical series and case reports.
Oral Estrogen Shows Strongest Association With PCT
Investigators analyzed Danish nationwide registry data collected between January 1995 and November 2024, identifying 438 women with a first-time hospital diagnosis of PCT and 43,800 matched controls. The median age of patients with PCT was 61.16 years.
Estrogen exposure (defined as at least 1 redeemed prescription within the preceding year) occurred in 35.16% of patients with PCT compared with 21.54% of controls. After adjustment for PCT-related comorbidities, estrogen-containing therapy was associated with increased odds of PCT (adjusted OR, 2.03; 95% CI, 1.66-2.49).
Estrogen-containing contraceptives (adjusted OR, 2.52), estrogen-only therapy (adjusted OR, 1.58), and combined estrogen-progestogen therapy (adjusted OR, 2.18) also showed associations. Route-specific analyses identified an association with oral therapy (adjusted OR, 2.44; 95% CI, 1.66-3.59), but not nonoral formulations.
"This nationwide matched case-control study found that estrogen-containing therapy was associated with incident PCT," the authors wrote. "In route-specific analyses, only oral therapy was associated with PCT, suggesting that route of administration should be considered when evaluating estrogen exposure as a potential risk factor for PCT."
Source
Erichsen PA, et al. JAMA Dermatol. Published online October 28, 2026. Doi:10.1001/jamadermatol.2026.4329