Trichoscopy may enhance the differential diagnosis of erythroderma.

There is a paucity of data concerning the usefulness of trichoscopy in patients with erythroderma. The aim of the study was to compare the trichoscopic features in erythroderma of various aetiologies. In total, 49 patients with a determined cause of erythroderma [including atopic dermatitis (AD), mycosis fungoides (MF), allergic contact eczema (ACE), psoriasis (Pso), Sézary syndrome (SS), drug reaction, pityriasis rubra pilaris (PRP), dermatomyositis (DM), actinic reticuloid (AR), crusted scabies (CS) and pemphigus foliaceus (PF)] were included in the study.

Pityriasis rubra pilaris-like eruption following administration of the BNT163b2 (Pfizer-BioNTech) mRNA COVID-19 vaccine.

We describe a case of a pityriasis rubra pilaris (PRP)-like eruption occurring following administration of the Pfizer-Biontech mRNA COVID-19 vaccine, with worsening of the condition following the second dose. To our knowledge, this is the first reported case of a PRP-like eruption as a cutaneous adverse event of the Pfizer-Biontech mRNA COVID-19 vaccine.

Interleukin 36 expression in psoriasis variants and other dermatologic diseases with psoriasis-like histopathologic features.

Background: Elevated epidermal interleukin (IL)-36 expression distinguishes psoriasis from eczematous dermatitis, but other psoriasiform dermatitides (PDs) have not been thoroughly investigated for IL-36 expression. In this study, we assess the IL-36 staining pattern (IL36-SP) in psoriasis variants and other PDs including lichen simplex chronicus (LSC), prurigo nodularis (PN), lichen planus (LP), tinea, pityriasis rubra pilaris (PRP), mycosis fungoides (MF), pemphigus foliaceus (PF), acute generalized exanthematous pustulosis (AGEP), impetigo (IMP), and syphilis (SY).

Methods: IL-36 immunostaining was performed on 307 cases of psoriasis and various PDs.

Alternative uses of ustekinumab for non-indicated dermatological conditions: a systematic review.

Ustekinumab is approved for the treatment of psoriasis and Crohn's disease. Because many dermatological conditions are due to immune-mediated development, ustekinumab may be effective in other conditions. A systematic review of the off-label uses of ustekinumab, as well as on-label adverse effect, was performed, reporting on clinical improvement.

Autoinflammatory keratinitzation diseases (AIKDs.

Autoinflammatory keratinization disease (AiKD) is a novel clinical concept encompassing diseases with a genetic background and mixed pathogenic mechanisms of autoinflammation and autoimmunity, leading to an aberrant keratinization of the skin. Recent advances in medical genetics have revealed genetic causes and/or predisposing factors for a number of AiKD's, such as mutations in IL36RN related with pustular psoriasis, acrodermatitis continua and hidradenitis suppurativa, in CARD14 in pityriasis rubra pilaris type V and some forms of pustular psoriasis, and in NLRP1 related with familial keratosis lichenoides chronica (KLC). It is suspected that AiKD pathophysiology would also be involved in non-monogenic disorders.

CARD14-associated papulosquamous eruption (CAPE) in a toddler responding to treatment with acitretin.

CARD14-associated papulosquamous eruption (CAPE) is a rare autosomal dominant dermatosis that presents classically in early childhood with clinical features of both psoriasis and pityriasis rubra pilaris (PRP). The disease is known to be refractory to topical and systemic therapies classically used for psoriasis, with the majority of reported cases requiring treatment with biologics, such as ustekinumab and secukinumab. We present a toddler with a clinical presentation consistent with CAPE and found to have a novel heterozygous variant of the CARD14 gene.

Altered replication stress response due to CARD14 mutations promotes recombination-induced revertant mosaicism.

Revertant mosaicism, or "natural gene therapy," refers to the spontaneous in vivo reversion of an inherited mutation in a somatic cell. Only approximately 50 human genetic disorders exhibit revertant mosaicism, implicating a distinctive role played by mutant proteins in somatic correction of a pathogenic germline mutation. However, the process by which mutant proteins induce somatic genetic reversion in these diseases remains unknown.

[Early onset of methotrexate-associated lymphoproliferative disorder mimicking Hodgkin's lymphoma].

Long-term methotrexate (MTX) treatment is known to cause MTX-associated lymphoproliferative disorder (MTX-LPD). A 58-year-old woman with psoriasis vulgaris and pityriasis rubra pilaris was treated with a combination of MTX and ustekinumab for 4 months when she developed generalized lymphadenopathy. The initial histopathological analysis indicated Hodgkin's lymphoma; however, assessing the patient's clinical history revealed the diagnosis of MTX-LPD.