Hidradenitis suppurativa tarda: defining an understudied elderly population.

BACKGROUND: Hidradenitis suppurativa (HS) is a chronic, devastating, multifactorial skin disease. Patients generally develop HS after puberty and the prevalence of the disease is assumed to decrease with higher age. Data outside the usual age range are limited, especially for elderly patients. OBJECTIVES: To investigate the prevalence, clinical characteristics and associated comorbidities among the elderly HS population. METHODS: Data were collected through a population-wide survey-based study within the Lifelines Cohort Study in the Netherlands. The clinical characteristics of elderly patients with HS (≥ 60 years) were compared with an adult population (< 60 years) with HS. The comorbidities in elderly patients with HS were compared with those of a non-HS sex- and age-matched elderly population in a 1 : 4 ratio. HS in the elderly was defined as active HS in patients aged 60 years and older. Within the HS elderly group, two subgroups were defined, late-onset HS (HS developed after 60 years of age) and persistent HS (HS developed from a younger age but continuing after 60 years of age). RESULTS: Within the Lifelines cohort 209 elderly patients with HS were identified as well as an adult (< 60 years) group with HS (n = 793) and a non-HS sex- and age-matched control elderly group (n = 810). The prevalence of HS among the elderly bootstrap analysis population was 0.8% [95% confidence interval (CI) 0.4-1.2]. A significantly higher age of HS symptom onset was found compared with the adult HS group: respectively, 40 vs. 23 years (odds ratio 1.056, 95% CI 1.05-1.07). Among the elderly HS cohort (in the Discussion, the HS tarda cohort) a female : male ratio of 1.7 : 1.0 and a higher family history for HS were found. Moreover, elderly patients with HS had a significantly higher risk of having HS-associated comorbidities compared with the sex- and age-matched controls. CONCLUSIONS: The prevalence of HS in the elderly is not rare. Among the elderly a shift from female predominance towards a lower female : male ratio in HS is observed. In addition, HS in the elderly showed significant variation in age of onset and involved body areas. Moreover, elderly patients with HS were more susceptible to multimorbidity. Finally, we propose defining HS in the elderly as 'HS tarda' and subdividing it as late-onset and persistent HS tarda.

Assessment tools and phenotype classification for hidradenitis suppurativa.

Hidradenitis suppurativa (HS) is a heterogeneous chronic relapsing skin disease. Several assessment tools are used to assess disease severity and to classify disease phenotype; however, no consensus exists. This review evaluates the various assessment tools and phenotypes, assessing their validity and reliability. Numerous assessment tools and phenotype classifications have been proposed for identifying various subtypes within the hidradenitis suppurativa disease spectrum. Each has a different purpose, such as use in daily practice or in clinical trial settings. Several assessment tools and phenotype classifications have been validated but not always with satisfactory results and often with studies showing divergent intra-rater reliability results. A consensus is needed for a validated, easy-to-use, and timesaving assessment tool for routine daily practice. For clinical trials, a validated and extensive assessment tool that also measures response to treatment is also needed.