Differences in frequency of vulvar dermatoses according to ethnicity: A study of a cohort of patients in a large diverse UK teaching hospital

The National Health Service Hospital Trust in East London, where we are based, serves an ethnically diverse population. The population of England and Wales as a total are 82% White, with the remaining 18% from Black, Asian, Mixed or Other ethnic groups. Tower Hamlets Borough, where one of our hospitals is based, had a population mix 41.8% Asian, 39.3% White and 7.4% Black in the 2021 UK census.¹ There is little data on the prevalence of different vulvar dermatoses in different ethnic groups. Lichen sclerosus is a common vulvar dermatosis in Caucasian women but we wanted to investigate the case mix across different ethnicities. We collected information on diagnosis and ethnicity in the population of patients attending the Vulvar Clinics at our hospitals over a total of 6 months in 2022 and 2023. The months were split to avoid duplication of patients and only data from individual patients was analysed. Diagnosis was made by a consultant dermatologist with subspecialty expertise in vulvar disease, sometimes in joint consultation with a consultant gynaecologist.

Data from 246 individual patients was collected. UK census data is collected into five ethnic groups as follows:—‘White’, ‘Asian or Asian British’, ‘Black or Black British, Caribbean or African’, ‘Mixed/Multiple’ and lastly ‘Other’ ethnic group.

The majority of patients seen were White (128/246) with 83 Asian, 17 Black, 15 Mixed/Multiple and 3 from ‘Other’ ethnic groups. Within the Asian group, the most common subdivisions included Asian Bangladeshi (38/83), Asian Indian (12), Asian Pakistani (14) and Asian other/non stated (19).

The mean age of patients in the three largest cohorts was 61 years—White, 46.2 years—Asian and 52.9 years—Black.

The five most common diagnoses varied according to ethnicity and are tabulated below (Table 1).

Lichen sclerosus was the most frequently diagnosed vulvar dermatosis in all ethnic groups except Asian. The mean age of patients of Asian ethnicity was also lower than the other groups. In Asian patients, lichen simplex was the most frequent diagnosis made. Further analysing the data, χ² test was performed on the 225 patients with diagnoses of either lichen sclerosus or lichen simplex (Table 2). There were statistically significant differences in patients receiving each diagnosis; according to ethnicity.

Controlling for age, the differences seen in each ethnic group were not statistically significant for lichen sclerosus. Results for lichen simplex were, although confidence intervals were wide. The increased odds of a lichen simplex diagnosis was 20.2 times higher in Asian patients (95% confidence interval [CI]: 4.48, 91.41; p < 0.001) and 11.71 times higher in Black patients (95% CI: 1.77, 77.59; p = 0.011) compared with White.

These results suggest lichen simplex of the vulva is more frequently the diagnosis behind a vulval presentation in Asian and Black patients compared to White patients.

Lichen simplex is often found in those with a genetic atopic predisposition.² Atopic dermatitis is known to occur more frequently in Black and Asian ethnic groups³ and may be an underlying cause of the increased rate of vulvar lichen simplex observed in these patients.

Genital hygiene varies worldwide according to cultural and religious practices.⁴ For example, in Islamic teachings, frequent washing of the genital skin is recommended—particularly after urination and defecation.⁵ This may be a further risk factor for vulvar lichen simplex as transepidermal water loss has been observed to increase in patients with lichen simplex chronicus and controls after more frequent washing.⁶ Washing practices may vary according to ethnic group and religion and further study would be required to investigate the difference observed in Asian, Black and White populations.

Iron deficiency has also been related to vulvar dermatitis⁷ and tends to be more common in premenopausal women. Further study is needed to investigate any difference in levels of serum iron or iron stores in patients of different ethnicities.

Further, health seeking behaviours may vary across different ethnic groups cultural backgrounds, potentially having influence on presentation. There is evidence from Pakistan of women in rural communities delaying health seeking for multiple reasons including using home remedies and consulting elder females in the community.⁸ More recent study has not found differences in health seeking behaviour based on ethnic origin or country of birth but convincing association with educational attainment.⁹ Further study of the multiple factors that may influence health seeking behaviour with regard to vulvar dermatoses is warranted.

In conclusion, lichen simplex of the vulva is most frequently seen in Asian and Black patients compared to White patients and our data demonstrates that there is a difference in vulvar diagnoses according to ethnicity. This may be due to a number of factors and further study is needed to allow more tailored investigation and management of these vulvar conditions in patients of different ethnicities.

Data collection and interpretation: Majeeda Patel. Data collection, journal search: Jade Simpson. Statistical analysis: Beth Stuart. Data collection and interpretation: Sujatha Thamban. Data collection and interpretation, journal search, manuscript preparation: Arucha Ekeowa-Anderson. All authors reviewed and contributed to manuscript preparation.

The authors declare no conflict of interest.

Not applicable.