Stripping of the stratum corneum in patients with psoriasis: production of prepinpoint papules and psoriatic lesions.

In patients with psoriasis, partial stripping of the stratum corneum induced minute erythematous and edematous, nonscaling papules six hours to seven days later. These "prepinpoint papules" PPPs) comparable to spontaneous PPPs, which we described earlier, appeared in 75 of 159 patients with active psoriasis but in none of 27 controls; 73% to 91% of these PPPs, depending on the activity of the disease, transformed into pinpoint papules. Histological and histochemical examinations of the PPPs showed infiltrates containing numerous polymorphonuclear leukocytes around the vessels and penetrating into the epidermis, partly destroying it. The earliest change in the epidermis was thinning of the granular layer without other features of psoriasis. Immunoglobulin G and complement deposits on stratum corneum (SC) antigen sites were found in the PPPs initially in about one third, and later in two thirds of the papules, whereas they were present in virtually all of the psoriatic pinpoint papules. Papules induced by stripping, similar to spontaneous PPPs, play a central role in the etiology of at least some forms of psoriasis. Polymorphonuclear leukocyte infiltrates and SC antibody binding are key features of the conversion of PPP to pinpoint psoriatic lesions.

Earliest clinical and histological changes in psoriasis.

Studies were performed in 89 patients with active psoriasis and in 10 normal volunteers. Areas of uninvolved skin of 10 x 10 cm in size were demarcated and closely observed for 14 days. In 54 patients with psoriasis, there developed very fine, erythematous papules almost skin level (with no scaling of the surface), which changed in the course of observation into typical pinpoint papules. Histological and histochemical studies of these finest changes, referred to as prepinpoint papules, revealed fairly abundant infiltrates composed in a large part of polymorphonuclears. The cells penetrated into the epidermis forming focally small accumulations in the stratum corneum. The granular layer became atrophied or blurred, the stratum corneum was orthokeratotic and there was no epidermal proliferation, i.e. no psoriatic features. Immunofluorescence studies showed in about 50% of prepinpoint papules in vivo fixed immunoglobulins, and in 20% of them also complement. The studies point to the role of polymorphonuclears in the earliest stages of the development of psoriatic lesions.

[Porphyria cutanea tarda caused by long-term use of femigen]. / Porfiria skórna pózna wywolana dlugotrwalym przyjmowaniem femigenu.

PIP: A case of porphyria cutanea tarda is reported in a healthy young woman who had been taking the oral contraceptive Femigen for 4 years. (author's modified)^ieng

Immunopathology of psoriasis.

Immunofluorescence (IF) studies by the direct and indirect methods demonstrate immunoglobulins and complement bound in vivo in psoriatic scales. The IF pattern is comparable to that of stratum corneum antibodies (SCAb) bound in vitro on specific substrate, as visualized by the indirect IF method. Formation of immune complexes can be responsible for the "squirting papilla" phenomenon, and conversion of the stratum corneum - which is normally an inaccessible antigen - into its reactive form seems to be brought about by proteases of polymorphonuclear leukocytes. Stimulation of protease production by polymorphonuclears appears to be an important factor in the pathogenesis of psoriasis. The stratum corneum of the epidermis is probably the target, and becomes an antigen for SCAb present in the circulation.

Pre-pin-point papules. Changes preceding pin-point lesions of psoriasis.

Skin areas of 10X10 cm were marked out and closely observed during 14 days in 22 patients with active and 18 cases with less active psoriasis. The first changes - minute papules, slightly erythematous, almost flush with the skin (pre-pin-point papules) appeared within this period and transformed after several days into pin-point lesions. Histological examinations performed in 25 pre-pin-point and 10 pin-point papules, as well as cytochemical studies have shown significant differences. In the pre-pin-point papules inflammatory infiltrates were in a great part polymorphonuclear, and the epidermis had no features characteristic of psoriasis. The performed studies have shown that the earliest changes preceding the appearance of spontaneous psoriatic papules are very much like those of provoked Koebner phenomenon.