Daijiworld Media Network - Copenhagen
Copenhagen, Nov 5: Oral estrogen-containing therapies have been associated with an increased risk of developing porphyria cutanea tarda (PCT), a rare condition that causes skin fragility and chronic blistering, according to a nationwide Danish study.
The findings suggest that both the type of estrogen treatment and its route of administration may play an important role in assessing the risk of developing the condition.
The matched case-control study analysed nationwide Danish registry data collected between January 1995 and November 2024. Researchers investigated the association between estrogen-containing therapies and new cases of PCT among women, addressing an evidence gap previously based largely on clinical case reports and case series.
The study included 438 women diagnosed with PCT for the first time and 43,800 age-matched female controls. Estrogen exposure was defined as having redeemed at least one prescription for an estrogen-containing treatment during the 12 months preceding the index date.
Among the PCT patients, 154 (35.16 per cent) had received estrogen-containing therapy, compared with 9,433 (21.54 per cent) among the control group.
After adjusting for other medical conditions associated with PCT, researchers found that estrogen exposure was linked to approximately twice the odds of developing the condition, with an adjusted odds ratio of 2.03.
The association was observed across all three categories of estrogen-containing treatments examined. Estrogen-containing contraceptives showed the strongest association, with an adjusted odds ratio of 2.52.
Estrogen-only therapy was also associated with an increased likelihood of PCT, with an adjusted odds ratio of 1.58, while combined estrogen and progestogen therapy recorded an adjusted odds ratio of 2.18.
Researchers also examined whether the route of administration influenced the association. Oral estrogen-containing treatments were linked to increased odds of developing PCT, with an adjusted odds ratio of 2.44.
However, treatments administered through non-oral routes were not found to be associated with the condition.
The findings provide further evidence that estrogen-containing therapies may be a risk factor for PCT. The condition is characterised by increased skin fragility and chronic blistering, particularly in areas exposed to sunlight.
Researchers noted that the association between oral estrogen use and PCT, which was not observed with non-oral administration, highlights the importance of considering the route of administration when assessing potential risks.
The study concluded that estrogen-containing therapies were associated with newly diagnosed PCT among women, with the findings extending across contraceptive preparations, estrogen-only treatments and combined estrogen-progestogen therapies.
The researchers said the route of administration should also be considered when evaluating PCT risk among individuals receiving estrogen-containing treatments.