Chronic hand eczema: is IL-36α helpful in diagnosis and classification?

Chronic hand eczema (CHE) is not a homogenous disease, necessitating complex differential diagnostics. Interleukin (IL) -1 family members are significantly up-regulated in ACD and psoriasis patients skin.

The present study aims to deepen the knowledge about clinical assessment and characterization of patients affected by chronic hand dermatitis (CHD) as well as to investigate the role of possible biomarkers which may help in the diagnostic process. An observational case-control study was performed enrolling 30 CHD patients and 20 healthy controls. Each patient underwent detailed medical history, clinical examination, epicutaneous patch test, and lesional skin biopsies for histological and immunohistochemical analysis.

Patient history, clinical examination and patch testing led us to a final CHD characterization in only 8/30 subjects (26.7%). In the remaining subjects, clinical and histological features suggested a diagnosis of psoriasis in 9/22 (30%) and idiopathic chronic hand eczema (CHE) in 13/22 (43.3%). Trying to find a possible marker for the latter dermatosis, we analyzed IL-1 family in all the recruited subjects. IL-1 members were increased in all conditions, but IL-36α was the only analyzed cytokine able to characterize patients who end up with a diagnosis of idiopathic CHE.

In conclusion, we can assess that medical history and patch testing remain essential investigations in CHD patients even if not always sufficient to perform a final diagnosis. Moreover, IL-1 members are probably involved in CHE skin inflammation, with IL-36α being a possible future biomarker which might help in the complex diagnostic process of CHE.