I'm always amazed that despite our many advances in science and medicine, new diagnoses and clinical entities still manage to pop up from time to time. Today I'm introducing one such occasion as detailed in the paper by Veronica Bonciolini and colleagues  (open-access available here) and the idea that 'cutaneous gluten sensitivity' (CGS) might be part and parcel of at least some presentation of non-coeliac gluten sensitivity (NCGS).
For those who might not know, NCGS describes part of a proposed spectrum of gluten-related conditions that lies outside of the classical 'gluten can affect health' autoimmune condition that is coeliac disease (CD). There is still some debate about the boundaries of NCGS and the precise diagnostic criteria (see here) but I'm of the opinion that there is something to see in this area and that, on occasion, there also may be psychological/behavioural issues associated with the label (see here) albeit with more research required.
Insofar as the relationship between cutaneous (skin) issues potentially associated with NCGS, well we have a precedent here with the link between dermatitis herpetiformis (DH) and CD, a skin condition manifesting as red raised patches of blisters often accompanied by severe itching. Treatment of DH normally involves a gluten-free diet (GFD) similar to the management of CD, although other preparations can also help soothe the itching and blistering.
The Bonciolini paper details the authors' efforts to document various cutaneous manifestations seemingly linked to NCGS and "to characterize the new pathologic entities known as CGS." To do this: "17 consecutive patients affected by NCGS after having considered gastroenterology and allergy in order to exclude other forms of gluten sensitivity such as CD and WA [wheat allergy]" were examined. The authors did a pretty good job of excluding conditions such as CD in their participant group as per their use of "serological assay with specific antibodies (anti-tissue transglutaminase antibodies (tTG) IgA and IgG, anti-endomysial antibodies (EMA), anti-gliadin antibodies (AGA), deamidated gliadin peptide (DGP) and total IgA) and esophagogastroduodenoscopy with multiple biopsies." Further researchers: "enrolled NCGS patients only after dietary elimination of gluten followed by DBPC [double-blind, placebo-controlled]" challenge. Skin samples were taken and various inspections of skin lesions carried out.
Results: "The common clinical feature of all the patients involved in this study, as well as the one detached from our clinical experience, was the severe itching." Researchers reported that the itching was difficult to treat with standard medications but "it showed prompt resolution when GFD was introduced" and "the reaction was faster than in DH patients." In terms of the skin lesions themselves, the authors describe them as "polymorphic" (I assume meaning that they took on various different shapes and sizes) and perhaps due to some pretty continual itching also took on a "psoriatic-like" appearance (as in similar to the plaques seen in psoriasis).
"The histological and immunopathological assays performed on skin samples exclude specific skin diseases of CD and the allergy skin tests exclude sensitization to gluten. Therefore, it is reasonable to assume that there may also appear skin manifestations among the extraintestinal manifestations of NCGS or that “cutaneous gluten sensitivity” (CGS) exists and needs to be characterized."
We await further investigations...
 Bonciolini V. et al. Cutaneous Manifestations of Non-Celiac Gluten Sensitivity: Clinical Histological and Immunopathological Features. Nutrients. 2015 Sep 15;7(9):7798-7805.
Bonciolini V, Bianchi B, Del Bianco E, Verdelli A, & Caproni M (2015). Cutaneous Manifestations of Non-Celiac Gluten Sensitivity: Clinical Histological and Immunopathological Features. Nutrients, 7 (9), 7798-7805 PMID: 26389946