Hidradenitis Suppurativa: Absence of Hyperhidrosis but Presence of a Proinflammatory Signature in Patients' Sweat

Abstract

The role of sweat glands in hidradenitis suppurativa has been largely neglected, despite the fact that its original designation, as "hidrosadénite phlegmoneuse", implied an inflammatory malfunction of the apocrine sweat glands as the underlying pathogenic driver. The aim of this study was to evaluate the role of apocrine sweat glands with respect to the proinflammatory environment of hidradenitis suppurativa. Therefore, gravimetric assessment and multiplex cytokine assays from sweat obtained from patients with hidradenitis suppurativa along with immunofluorescence cytokine/chemokine analysis of lesional apocrine glands- bearing hidradenitis suppurativa skin were performed. Gravimetric assessment of 17 patients with hidradenitis suppurativa revealed that the condition is not associated with hyperhidrosis. However, patients seem to be more affected by subjective sweating. The current data identified a complex proinflammatory signature in hidradenitis suppurativa sweat characterized by a significant upregulation of monocyte chemoattractant protein-1, interleukin-8 (CXCL8), and interferon-γ. In agreement with this, a strong in situ expression of these mediators could be observed in apocrine glands of lesional hidradenitis suppurativa skin. These data shed new light on the proinflammatory capacity of apocrine sweat glands in hidradenitis suppurativa, which may lead to reconsideration of the role of sweat glands in hidradenitis suppurativa pathology.

Fig. 1

Patients with hidradenistis suppurativa (HS) are more affected by subjective sweating. (a) Patients with HS scored a higher mean Dermatology Life Quality Index (DLQI) than the healthy control group (standard error of mean (SEM) 7.2 ± 2.0 vs 0.7 ± 0.2 p ≤ 0.001; box-whisker plot). (b) In addition, patients with HS were statistically significantly more affected by subjective sweating than the healthy control group (p ≤ 0.05; box-whisker-plot); and (c) report their sweating more often as a burning, itching or painful sensation (p ≤ 0.05; bar chart). Filled grey bars: HS group; striped bars: healthy control group. HDSS: Hyperhidrosis Disease Severity Scale.

Fig. 2

Hidradenistis suppurativa (HS) disease severity correlates with subjective sweating. HS severity according to mHSS proves a significant correlation to Hyperhidrosis Disease Severity Scale (HDSS) and Dermatology Life Quality Index (DLQI).

Fig. 3

Hidradenistis suppurativa (HS) does not correlate with a higher incidence for hyperhidrosis. Both (a) at rest and (b) under excerise, the healthy control group revealed a trend to higher gravimetric sweat production than the HS group (p = 0.71). (c, d) Gravimetric sweat measurement at rest significantly correlated with that during exercise in both groups. Grey bar: HS group; striped bar: healthy control group.

Fig. 4

Hidradenistis suppurativa (HS) sweat glands express proinflammatory cytokines. (a) Significantly enhanced expression of interleukin (IL)-8, monocyte chemoattractant protein (MCP)-1, and interferon (IFN)-γ (but not for IL-6) in apocrine glands of lesional axillary HS skin sections. (b) Isotype control antibodies served as control. Representative immunofluorescence labelings for the indicated cytokines (red) and DAPI staining (blue) of n=13 patients. Bar: 100 µm.