Histopathologic findings characteristic of CARD14-associated papulosquamous eruption.

BACKGROUND: Pathogenic mutations in caspase recruitment domain-containing protein 14 (CARD14) lead to CARD14-associated papulosquamous eruption, which shares clinicopathologic findings with psoriasis and pityriasis rubra pilaris. We aimed to describe distinguishing histopathologic features of CARD14-associated papulosquamous eruption. METHODS: This retrospective study examined the histopathologic features of specimens from patients with confirmed CARD14-associated papulosquamous eruption and adult patients with plaque psoriasis and pityriasis rubra pilaris. RESULTS: Lesional skin biopsies from patients with CARD14-associated papulosquamous eruption consistently showed alternating checkerboard parakeratosis and orthokeratosis, acanthosis without acantholysis, and dilated vessels in the dermal papillae, with some cases also showing follicular plugging. CONCLUSION: CARD14-associated papulosquamous eruption has a range of findings, with a predominance of features typically associated with pityriasis rubra pilaris.

Use of Biologics in Pityriasis Rubra Pilaris Refractory to First-Line Systemic Therapy: A Systematic Review [Formula: see text].

Pityriasis rubra pilaris (PRP) is an uncommon, inflammatory, papulosquamous skin disease. Treatment of PRP is challenging as the disease is often refractory to conventional therapies, such as retinoids and methotrexate. There has been an increasing number of studies reporting the successful use of biologic therapy in patients with PRP; however, the data on the efficacy and safety are limited. Our objective was to evaluate the existing evidence for utilizing biologics, whether alone or in combination with established systemic therapies, in patients with treatment-resistant PRP. We systematically reviewed evidence within Medline and Pubmed databases between January 1, 2000, to March 31, 2019. Articles consisted of patients diagnosed with PRP who have failed to respond sufficiently to first-line systemic therapies, or who had comorbidities that precluded their use. In total, 363 unique articles were identified, 56 of which were considered relevant to the clinical question. Of the 56 articles highlighted, 35 met the inclusion criteria and were limited to case series and case studies. Therapy with biologics was found to be successful for both monotherapy (81.1% [27/33]) and when used in combination with existing systemic therapies (87.5% [14/16]). The existing evidence suggests that biologics may be regarded as a tool for PRP treatment alone or in combination therapy with existing treatments, although large-scale randomized clinical trials are necessary to better assess their efficacy and safety.

Pityriasis rubra pilaris with acantholysis and lichenoid histology.

Acantholytic foci have been reported several times in pityriasis rubra pilaris (PRP). Lichenoid tissue reactions were also mentioned in the literature regarding PRP. We report a 58-year-old patient who, after having colon cancer, had PRP with biopsies showing acantholytic lesions and a heavy lichenoid lymphocytic infiltration. Investigation by serial sectioning of the acantholytic lesion suggested an involvement of the intraepidermal eccrine duct and further investigation with carcinoembryonic antigen (CEA) staining demonstrated a CEA-positive eccrine duct in the acantholytic foci. We suggest that acantholysis in PRP is induced by proteolytic enzymes, urea, and other substances in eccrine sweat in keratin-plugged acrosyringia. This patient had a combination of three relatively rare features of PRP-acantholysis, lichenoid reaction, and a cancer background.

Topical treatment of pityriasis rubra pilaris with calcipotriol.

From a clinical, histological and therapeutic point of view, psoriasis and pityriasis rubra pilaris share important characteristics. Recently, calcipotriol has been shown to be an effective treatment in psoriasis, and we report three patients with pityriasis rubra pilaris who showed a favourable response to topical therapy with calcipotriol. In one case, analysis of markers for epidermal growth, differentiation and inflammation revealed reduction of suprabasal expression of keratin 16, and the number of T lymphocytes, monocytes and macrophages. It is of interest that a reduction of the recruitment of cycling epidermal cells, which is a consistent response pattern during treatment of psoriasis, was not observed during treatment of pityriasis rubra pilaris.

[Marking disorders of keratinization by means of lectins. II. Keratosis pilaris, lichen spinulosus, porokeratosis, lichen striatus and pityriasis rubra pilaris]. / Marcaje mediante lectinas de trastornos en la queratinización. II. Queratosis pilaris, liquen espinuloso, poroqueratosis, liquen estriado y pitiriasis rubra pilaris.

Lectins are used to study four cases of keratosis pilaris, four of lichen spinulosus, 11 of porokeratosis, 8 of striated lichen and one case of pityriasis rubra pilaris, with the aim of providing data to improve knowledge of the histogenesis of these processes.

Demonstration of leukotriene B4 in the scale extracts of psoriasis and inflammatory pustular dermatoses. Correlation with leukocyte chemotactic activity and C5a anaphylatoxin.

We carried out quantification of the levels of leukotriene B4 (LTB4), a highly potent cell membrane-derived leukocyte chemotactic factor, in scale extracts of psoriasis and related inflammatory dermatoses characterized by sterile subcorneal pustule formation by using radioimmunoassay. A small amount of LTB4 was demonstrable even in extracts from non-inflammatory stratum corneum, but larger amounts were detected in the scale extract from pustular psoriasis and in those from psoriasis vulgaris. There was a significant correlation between the LTB4 and C5a levels in scale extracts, suggesting that complement activation and generation of LTB4 are a closely related event in psoriatic lesions. However, in contrast to highly significant correlation noted between the amount of C5a and chemotactic activity for polymorphonuclear leukocytes (PMN) detectable in scale extracts, LTB4 levels correlated only marginally with the chemotactic activity.

Pityriasis rubra pilaris: a clinico-pathological and therapeutic study with special reference to histochemistry, autoradiography, and electron microscopy.

Five patients with pityriasis rubra pilaris (PRP) were analyzed by means of light and electron microscopy as well as by histochemistry and autoradiography. The results were compared with findings in psoriasis vulgaris. In PRP we found a moderate increase of the labeling index of epidermal cells, a highly increased labeling index of dermal infiltrating cells, and a mild spongiosis, and in the stratum granulosum, a decreased number of tonofilaments and an increased number of keratinosomes. The horny layer in PRP showed a pronounced histochemical and electron microscopical parakeratosis, even when histological parakeratosis was absent. In contrast with psoriasis vulgaris, there was no exocytosis of polymorphonuclear leucocytes into the epidermis, the papillomatosis index was normal, and there were no tortuous capillaries in the dermal papillae. The stratum granulosum was always present and sometimes thickened, showing electron microscopical changes different from those referred to in psoriasis. These changes point to a relatively distinct pattern of epidermal changes in PRP.

Pityriasis rubra pilaris: epidermal cell kinetics.

Epidermal proliferative kinetics were studied in a patient with pityriasis rubra pilaris. Elevated proliferative indices (flash labelling and mitotic indices) were apparent compared with normal epidermis and measurements of the birth rate indicate that the rate of epidermal cell production was similar to that found in psoriasis, and equalled 11.8 cells/1000 germinative cells/h; this suggests a cell cycle time of 60 h. Contemporaneous measurements of the rate of entry into DNA synthesis showed values similar to the rate of entry into mitosis; hence there is no G2 cell loss as appears to occur in the hyperproliferative psoriatic epidermis.