Pregnancy and psoriasis – for better or for worse?

Pregnancy is clearly associated with profound changes in the female hormonal environment, especially oestrogen and progestogen.  These changes may modulate the biological and immune responses in the skin and contribute to anecdotal reports of an improvement in psoriasis during pregnancy.  Most of the published studies are retrospective and reflect a mixed picture – some show improvement of psoriasis during pregnancy, whilst others show a worsening.  However, taking all the older studies together, they still point to an overall improvement in psoriasis during pregnancy¹. 

One of the few prospective studies was carried out by Murase et al on 47 pregnant women with psoriasis and 27 non-pregnant patients in a control group².  The body surface area (BSA) involved was used as the objective disease measure and assessed 5 times over a period of 1-year.  Hormone levels (progesterone and oestrogens) were also measured.  During pregnancy 55% or patients reported improvement in their psoriasis, 21% reported no change and 23% reported worsening.  This observation is in line with other studies which generally show that during pregnancy, approximately twice as many psoriatic patients report improvements as those reporting a worsening of skin manifestations^3,4.  The beneficial effect of pregnancy appears to have been primarily mediated by a rise in oestrogen levels, but was not related to a rise in progesterone. 

Note, however that despite the beneficial effects of pregnancy on psoriasis, in the immediate post-partum period several studies showed a flare in symptoms, which was linked to a sudden fall in oestrogen and progestogen levels.  However, the evidence suggests that this “flare” in the postpartum period was a return to the pre-pregnancy baseline, rather than an actual worsening of symptoms. 

Regarding pregnancy and psoriatic arthritis, a similar pattern applies⁵.  A recent prospective, multicentre study from Norway included >100 pregnant women with psoriatic arthritis.  Researchers found that disease activity tended to decrease in pregnancy, but increased significantly in the postpartum period, before returning to baseline within 1-year.  

Making women with psoriasis aware of these possible changes during pregnancy is important in the overall management of their disease. 

 Key points

• During pregnancy there is a strong tendency for psoriatic skin disease and arthritis to improve significantly.
• This improvement is probably an effect of oestrogen, rather than progestogen
• In the postpartum period there is a tendency for both skin disease and arthritis to flare-up, though this is probably a return to pre-pregnancy (baseline) levels of disease, rather than a true worsening.
• Women with psoriasis should be made aware of these likely changes in their disease during pregnancy

Dr David Ashton MD PhD

 Scientific References

1. Mowad CM, Margolis DJ, Halpern AC,et al. Hormonal influences on women with psoriasis. Cutis. 998; 61:257-60.
2. Murase JE, Chan KK, Garite TJ, et al. Hormonal effect on psoriasis in pregnancy and postpartum. Arch Dermatol. 2005;141:601–606.
3. Raychaudhuri SP, Navare T, Gross J, Raychaudhuri SK. Clinical course of psoriasis during pregnancy. Int J Dermatol. 2003;42:518–520.
4. Boyd AS, Morris LF, Phillips CM, Menter MA. Psoriasis and pregnancy: hormone and immune system interaction. Int J Dermatol. 1996; 35:169–172.
5. Ursin K, et al.  Disease activity of psoriatic arthritis during and after pregnancy: A prospective multicenter study. Arthritis Care Res 2018; DOI:10.1002/acr.23747.