Irritant contact dermatitis (ICD) is a very common occupational skin disease but its pathogenesis remains poorly understood. The application of topical irritants was used to study cellular mechanisms of ICD, by sampling tissue from skin biopsies, suction blisters and skin window chambers. The early (upto 6h) and late (upto 48h) histopathological changes were investigated in patients following the application of 80% nonanoic acid (NA) and 5% sodium lauryl sulphate (SLS). The irritants were titrated on volunteers to produce similar grades of mild erythema for the two irritants. SLS caused minimal early damage but induced parakeratosis and spongiosis at 24h. SLS also induced a prominent dermal neutrophilic infiltrate and epidermal infiltration. In contrast, NA induced basal cell layer apoptosis without significant inflammatory infiltration. These cells were later shown to be Langerhans cells (LC). The different patterns of epidermal damage prompted the quantification of the cytokines IL-8 (a neutrophil chemoattractant) and IL-1α (a key pro-inflammatory cytokine) by ELISA in suction blister fluid in patients and volunteers after irritation with NA and SLS. It was shown that NA induced IL-1α upto 24h post irritation, but minimal IL-8. SLS, however, induced IL-8 at 6 and 24h. This result was in keeping with the histopathological findings above. Another aspect of ICD studied was the investigation of LC after NA irritation by confocal microscopy, in both volunteers and patients with ICD. There was a marked reduction of LC in both groups, but greater in patients. The morphology of the LC was altered with a reduction in both the number and lengths of dendrites with time after irritation.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:661771 |
| Date | January 1999 |
| Creators | Shahidullah, Hossain |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/22624 |
Page generated in 0.0065 seconds