October 2024 digest

ISAD plans a celebration of the Centennial birthday anniversary of Georg RAJKA (1925-2013) next year in Melbourne, Australia

Dear Colleagues, Dear Friends,

Fleeing Hungary, his native country, after the Soviet occupation, Georg RAJKA made in Sweden then Norway an outstanding and very original academic career centered on Prurigo Besnier/AD. Prurigo Besnier was indeed the name used in Scandinavia around 1960 to designate AD. Contrary to psoriasis, naming AD never achieved a total consensus. In the second millennium, perpetuating naming difficulties still complicates our patients’ journey to optimal care.

To prepare the centennial Jubilee at the 15th AD symposium of Melbourne, organized by John SU, the Ph.D. thesis of G. RAJKA “Studies in hypersensitivity to molds and staphylococci in Prurigo Besnier”, published in 1963, is now available on our website in 3 articles published in the Acta Dermato-Venereologica, with the kind permission of the Journal. It describes the very meticulous investigations conducted in a series of 1200 patients seen at Karolinska Hospital, Stockholm.

Of G. RAJKA, dermatologists recall generally the top cited HANIFIN and RAJKA criteria, but several other seminal contributions, especially on experimental itch, preceded the criteria paper read at the first international symposium on AD he organized in Oslo in 1979. His now rare book, Atopic Dermatitis, published in 1975 by SAUNDERS, as the volume 3 in the series “Major problems in Dermatology” edited by Arthur ROOK, deserves a second look. It was written in the context of IgE discovery and the domination of immuno-allergology, which however had failed to explain delayed reactions to atopens.

In 2024, dermatologists access “live” pathophysiology experiments, with drugs which can hit with a high specificity defined molecular targets, combined with the methodology of randomized clinical trials.  However, we still cannot answer a question raised by early investigators: is AD a primary TH2 skewed inflammatory skin disorder or a neurodermatitis where pruritus leads to a secondary TH2 predominant inflammation?

In 1975, G. RAJKA made clear that he understood AD as a skin disease due to an abnormal pruritus threshold with secondary inflammation and barrier defects. His theory, based on experiments using trypsin as itch elicitor is a more elaborated version of Jacquet’s theory of 1904 that pruritus precedes inflammation in AD “C’est le prurit qui est éruptif”.

The controversy will continue next year in Melbourne!

Best wishes,

Alain TAÏEB
President ISAD

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