Studies on the pH gradient in normal and ichthyotic human skin
1998 (English)Licentiate thesis, comprehensive summary (Other academic)
In search for pathogenetic mechanisms underlying hyperkeratosis, we examined the pH gradient across the stratum corneum in normal and ichthyotic skin. Twenty students and employees, (12 men and 8 womenaged 25-69 years) served as controls. Patients with ichthyoses were recruited from the outpatient clinic (13 men aged 12-71 years). Diagnosis was made on the basis of clinical examination and serum lipid electrophoresis.
For recording pH values, a flat glass electrode was repeatedly applied to the skin during tape stripping of volar forearm skin. Before stripping, surface pH (mean±SD) was higher in autosomal dominant ichthyosis vulgaris (IV) (5.2±0.3; n=7) than in x-linked recessive ichthyosis (XRI) (4.6±0.2; n=6) and healthy control skin (4.5±0.2; n=7). This comparision was made between men since a sex difference was observed when comparing men and women in the control group (4.5±0.2; n=7 for men and 5.3±0.5 for women).
Removal of stratum corneum, which required 170-200 strippings in ichthyotic skin and 100-120 strippings in healthy control skin, dicsclosed markedly different pH variations in the two types of ichthyoses. The major abnormality in IV skin was that a neutral pH was attained already after half the total number of strippings through the hyperkeratotic stratum corneum, which may reflect a lack of acidickeratohyalin breakdown products in this condition.This in contrast to XRI where the pH gradient was less steep and eventually plateaued at pH 6.2-6.6 instead of at 6.7-7.0 as in normal skin. A likely explanation is the accumulation of cholesterol sulfate in lower stratum corneum which occurs in XRI.
Our results suggest that the 'acid mantle' of normal skin, which penetrates deep into the stratum corneum, is the combined result of cornification-associated organic acids and back-diffusion of of acid material from the surface. Since comeocyte desquamation involves many pH dependent enzymes, abnormalities in the transcomeal pH gradient might play a role in the pathogenesis of ichthyoses.
Place, publisher, year, edition, pages
Linköping: Linköpings universitet , 1998. , 29 p.
Linköping Studies in Health Sciences. Thesis, ISSN 1100-6013 ; 36
keratinization, hyperkeratosis, desquamation, filaggrin, cholesterolsulfate, tape stripping
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:liu:diva-28174Local ID: 12996ISBN: 91-7219-077-9OAI: oai:DiVA.org:liu-28174DiVA: diva2:248725
1998-07-29, Patologens föreläsningssal, Hälsouniversitetet, Linköping, 13:00 (Swedish)
Papers, included in licentiate theses, are not registered and included in the posts from 1999 and earlier.2009-10-082009-10-082013-07-08