A pilot study of unemployment in patients with hidradenitis suppurativa in Denmark

Dear Editor, Hidradenitis suppurativa (HS) is a chronic, inflammatory and relapsing skin disease, characterized by repeated outbreaks of painful inflamed nodules in the apocrine gland‐bearing regions (armpits, genital area, groin, breasts and perianal region). These nodules can progress to abscesses, sinus tracts (tunnels) and scarring.1 The estimated prevalence is 1–4% worldwide and HS is approximately three times more common in women than in men.1 HS is associated with significant disability and handicap. The lesions are often painful and lead to loss of mobility. Clothing can often hide the clinical signs of the disease, but the active condition is not infrequently associated with a malodorous discharge that stains clothing, and HS is therefore often accompanied by embarrassment, disabling social stigma, low self‐worth and impacts interpersonal relationships, education and work.2 3 Overall, HS has a substantial negative effect on the quality of life (QoL) of the affected persons. All adult patients diagnosed with HS and undergoing outpatient treatment were invited to complete a questionnaire that was sent to them by post with a prepaid return envelope. Statistical power was assessed as suggested by Norman et al.4 The Dermatology Life Quality Index (DLQI) was proposed in 1994,5 as a measurement for QoL for dermatology patients. The DLQI has been used as a secondary end point in several medical trials for HS treatments.6 The tool assesses the effect that skin conditions have on the QoL of affected individuals, based on symptoms, embarrassment and daily activities. Scores range from 0 (no effect on QoL) to 30 (extreme effect).7 The Major Depression Inventory (MDI) is a self‐reported questionnaire designed to gauge a level of depression on a scale from 0 to 50. It can be used to diagnose depression, using a cut‐off point of 26 (sensitivity 1, specificity 0·82).8 It covers the diagnostic questions for depression for both the Diagnostic and Statistical Manual of Mental Disorders (DSM)‐IV and International Statistical Classification of Diseases and Related Health Problems (ICD)‐10 classifications. Locations were divided into axillae, submammary region, buttocks, inguinal area, pubic area, genitals and elsewhere. Patients were asked to state how many flares they experienced in these locations during the last 6 months. Answers were divided into 0, 1–3, 3–10 and more than 10 occasions. Statistical analysis included simple descriptive statistics and nonparametric statistics to identify statistically significant differences in univariate analysis due to the limitations of the dataset. Of 608 questionnaires sent, 383 people responded to the survey (63%). For population characteristics see Table 1. Population characteristics MNA6, median number of abscesses during the last 6 months; DLQI, Dermatology Life Quality Index; MDI, Major Depression Inventory. Population characteristics MNA6, median number of abscesses during the last 6 months; DLQI, Dermatology Life Quality Index; MDI, Major Depression Inventory. Responders were divided into: employed (n = 215), unemployed (n = 72) and noneligible (student or retired) (n = 96). The unemployment rate of adult HS patients, eligible for a job, was 25·1%, compared with 6·2% for the general population (December 2014; Statistics Denmark).9 A one‐sample binominal test comparing the unemployment rate of patients with HS with the general population found a significant difference (P < 0·0001). A Chi‐squared test showed no significant difference in unemployment rate between male and female patients (P < 0·694). A Mann–Whitney U‐test showed that unemployed patients reported a significantly higher occurrence of flares in the axillae (P < 0·004), submammary region (P < 0·047) and elsewhere (P < 0·0001). The overall mean DLQI was 8·75. Employed patients (mean 7·20) had a significantly lower DLQI than both unemployed (mean 11·63, Mann–Whitney U‐test, P < 0·0001) and noneligible (mean 9·32, P = 0·008) patients. However, there was no significant difference between unemployed and noneligible patients (P = 0·197). The mean MDI of the population was 15·22. Employed patients with HS scored a mean of 11·7 (SD 9), unemployed patients scored a mean of 23·6 (SD 12·6) while noneligible patients scored a mean of 16·7 (SD 11·8). Employed patients with HS had a significantly lower MDI score than the unemployed (Mann–Whitney U‐test, P < 0·0001) and noneligible (P < 0·001) patients. Unemployed patients with HS had a significantly lower MDI score than the noneligible patients (P < 0·001). The mean duration of education was 13·1 years (SD 2·8) (including 9 years of compulsory education). Employed patients with HS had a mean of 13·5 years (SD 2·7), the unemployed had a mean of 12·4 years (SD 3·0). Employed patients had a significantly longer education than unemployed ones (Mann–Whitney U‐test, P < 0·001). Patients suffering from HS have a higher rate of unemployment than the background population (25·1% vs. 5·9%). The data on the control group were of a general nature and did not allow a multivariate analysis. Univariate analysis was done comparing employed and unemployed patients with HS, in order to identify possible significant factors. The unemployed patients more commonly experience axillary and mammary involvement, they score higher on the MDI (23·6 vs. 11·7) and DLQI (11·63 vs. 7·20). An unemployment rate of 25·1% for patients with HS implies a significant impact of this disease and/or its comorbidities. Skin diseases not only cause skin problems, but are often associated with psychosocial consequences. Jobanputra et al. report an unemployment rate of 36% among South African dermatology patients of all diagnoses including occupational dermatoses and hand eczema.10 The unemployment rate among patients with hand eczema has been reported as 6·7% in Italy and 5·0% in Sweden.11 12 Other inflammatory skin diseases such as psoriasis have reported unemployment rates of 5·3–6·2% in Canada,13 and 9% in the U.S.A.14 U.K. patients with acne were examined in 1986 and Cunliffe found an unemployment rate of 16·2% for men and 14·3% for women, compared with 9·2% for men and 8·7% for women in the background population, both differences being statistically significant.15 Other studies of absenteeism found 58·1% of employed patients with HS missed work, and that HS causes an average loss of 33·6 ± 26·1 work days per year.2 Together, this suggests the disease's significant impact on work status. No data were available on the specific reason for unemployment. It could be speculated that the pain and psychological aspects of HS affect a patient's abilities to maintain a job. Alternatively, the burden of HS might prevent patients from undertaking an education, which would greatly diminish the employment options available. The reported distribution of lesions suggests that the majority of impairment is caused by lesions affecting the most common sites; alternatively the increased flare incidence in the axilla, submammary region and other regions could be interpreted as increased severity in lieu of a validated severity score. Data was collected by mail, and therefore we could not accurately verify disease severity. Because of this we could not correlate DLQI or MDI to disease severity, but the DLQI has previously been used as a secondary end point in trials,6 and correlates to lesions/month16 and Hurley stage.2 No severity data or data on obesity or smoking were collected. Employed patients’ highest achieved education was significantly higher than that of the unemployed patients. No firm conclusions can be made regarding causality in this cross‐sectional study. The MDI scores suggest that employed patients with HS appear to be less depressed than the unemployed patients. Direction (causality) of the association cannot be determined based on cross‐sectional studies. Finally, the response rate of 63% implies that the true rate of unemployment in the HS population might be even higher than reported, as a healthy worker bias is likely. Conflicts of interest: none declared.