Dermatoses neutrofílicas: parte II

Autoinflammatory Keratinization Diseases-The Concept, Pathophysiology, and Clinical Implications

Recent advances in medical genetics elucidated the background of diseases characterized by superficial dermal and epidermal inflammation with resultant aberrant keratosis. This led to introducing the term autoinflammatory keratinization diseases encompassing entities in which monogenic mutations cause spontaneous activation of the innate immunity and subsequent disruption of the keratinization process. Originally, autoinflammatory keratinization diseases were attributed to pathogenic variants of CARD14 (generalized pustular psoriasis with concomitant psoriasis vulgaris, palmoplantar pustulosis, type V pityriasis rubra pilaris), IL36RN (generalized pustular psoriasis without concomitant psoriasis vulgaris, impetigo herpetiformis, acrodermatitis continua of Hallopeau), NLRP1 (familial forms of keratosis lichenoides chronica), and genes of the mevalonate pathway, i.e., MVK, PMVK, MVD, and FDPS (porokeratosis). Since then, endotypes underlying novel entities matching the concept of autoinflammatory keratinization diseases have been discovered (mutations of JAK1, POMP, and EGFR). This review describes the concept and pathophysiology of autoinflammatory keratinization diseases and outlines the characteristic clinical features of the associated entities. Furthermore, a novel term for NLRP1-associated autoinflammatory disease with epithelial dyskeratosis (NADED) describing the spectrum of autoinflammatory keratinization diseases secondary to NLRP1 mutations is proposed.

Dermatitis Cruris Pustulosa et Atrophicans: Scarring Alopecia Beyond Scalp Hair

Dermatitis Cruris Pustulosa et Atrophicans (DCPA) was first described in 1952 in Nigeria and is nowadays regarded as a type of chronic folliculitis of tropical areas. It is often limited to the lower limbs of young adults, mostly in the second to third decades, with a unique clinical picture characterized by chronicity, relentless progression, therapy refractoriness, and permanent cicatricial changes. Trauma, occlusion, and microorganism selection contribute for its etiopathogenesis, which is deemed multifactorial but still incompletely understood. Despite its conspicuous clinical features, awareness of DCPA is apparently low, hence probably overlooked. We herein summarize the current state of knowledge regarding this distinct entity, and further present the first report in a patient from Bangladesh, and concurrently the first in Europe. Paucity of data, and unraveled definite etiology and treatment, highlight the need for further studies.

Subcorneal pustular dermatosis: Comprehensive review and report of a case presenting during pregnancy

Subcorneal pustular dermatosis (SPD), also known as Sneddon-Wilkinson disease, is a rare, relapsing, sterile pustular eruption of unknown etiology that develops most commonly in middle-aged or mature women. This article reviews the presentation, associations, and management of the condition and highlights advances in pathophysiology. Onset of SPD during pregnancy has not been reported. Herein, we report a case of SPD that developed during pregnancy. The patient was treated with dapsone without complications for her or the fetus. An association between T helper (Th) 17 and Th2 environments in the development of SPD has been advocated. Pregnancy is characterized by a predominance of Th2 responses and increased interleukin-17 levels and thus may favor the development of the condition.

Sneddon-Wilkinson Disease and Monoclonal Gammopathy of Undetermined Significance in the Elderly: Case Report

Sneddon-Wilkinson disease (SWD) or subcorneal pustular dermatosis is considered a rare pustular skin disease with chronic relapsing course. An association between SWD and other chronic conditions, such as IgA or IgG monoclonal gammopathy of undetermined significance (MGUS), IgA myeloma, pyoderma gangrenosum, thyroid gland disorders, and neoplastic diseases other than MGUS/myeloma, is known. We describe the case of a 92-year-old male patient with SWD and a concurrent IgG MGUS who had been treated with systemic betamethasone, topical mometasone furoate, and methylprednisolone aceponate, with a complete and durable resolution of symptoms and skin lesions without side effects. Systemic and topical steroids were very effective and well tolerated in our patient. This is the second case reported in the literature on the efficacy of a corticosteroid regimen in SWD in a fragile patient. This therapeutic approach (instead of dapsone therapy) has been used due to its relatively good safety profile.

Distinguishing pustular psoriasis and acute generalized exanthematous pustulosis on the basis of plasmacytoid dendritic cells and MxA protein

BACKGROUND

Distinguishing acute generalized exanthematous pustulosis (AGEP) and pustular psoriasis (PS) can be challenging. Staining for plasmacytoid dendritic cells, or PDCs (producer of IFN-α/β), and MxA (an IFN-α/β inducible protein) may help discriminate these entities.

METHODS

Forty-three cases of AGEP and PS were compiled from two academic institutions. All cases were examined for CD123+ PDCs, eosinophils, acanthosis, papillomatosis, suprapapillary plate thinning, tortuous dilated capillaries, single necrotic keratinocytes, papillary dermal edema, vasculitis, eosinophil exocytosis, intraepidermal pustules, and subcorneal pustules. A subset of cases (n = 26) was stained for MxA.

RESULTS

Perivascular and intraepidermal PDCs, dilated tortuous vessels, and MxA expression in the dermal inflammatory infiltrate were significantly (P < 0.05) in favor of a diagnosis of PS. The absence of PDCs and presence of eosinophils favored a diagnosis of AGEP (P < 0.05).

CONCLUSIONS

We found compelling evidence for the use of CD123 to highlight PDCs in these cases. The presence of PDCs and expression of MxA in dermal inflammatory infiltrate, as well as absence of eosinophils and presence of tortuous dilated capillaries favored a diagnosis of PS. Expression of MxA in the dermal infiltrate corresponds with a Th1 pathway in PS and may indicate a Th1 component in the early initial phase of AGEP.

Neutrophilic dermatoses: Kids are not just little people

Neutrophilic dermatoses are a group of inflammatory skin disorders characterized by an overactive innate immune system with dysregulation of neutrophils without underlying infectious etiology. The major representative conditions discussed are Sweet syndrome; pyoderma gangrenosum; neutrophilic eccrine hidradenitis; palmoplantar eccrine hidradenitis; subcorneal pustular dermatoses; bowel-associated dermatosis arthritis syndrome; and synovitis, acne, pustulosis, hyperostosis, and osteitis. We will also discuss other neutrophilic conditions present almost exclusively in the pediatric population, including congenital erosive and vesicular dermatosis with reticulated supple scarring and the recently described group of autoinflammatory diseases. The clinical characteristics, diagnostic approach, and treatment management in the pediatric and adult population are discussed.

Acute generalized exanthematous pustulosis associated with spider bite

Acute generalized exanthematous pustulosis (AGEP) is an acute febrile rash, usually induced by drugs, which recently has been linked to spider bite. We report a case of a male patient, 48 years old, with an erythematous rash accompanied by fever and small non-follicular pustules. He reported previous pain in the buttock with the onset of a necrotic plaque. The lesion was compatible with spider bite of the genus Loxosceles. According to the EuroSCAR group instrument, the patient scored +10 indicating definite diagnosis of AGEP. As the patient had a compatible lesion and had no other triggers of AGEP, in an Loxosceles endemic area, the AGEP would be associated with spider bite, as described in other publications.

Bullous, pseudobullous, & pustular dermatoses

Several dermatoses are typified by the formation of spaces (blisters; bullae) within or beneath the epidermis. These may be acellular or filled with particular species of inflammatory cells. Etiological categories include infectious, immune-mediated, genetic, drug-related, and idiopathic lesions. Examples of such disorders include impetigo, Herpes virus infections, pemphigus, bullous pemphigoid and pemphigoid gestationis, epidermolysis bullosa acquisita, IgA-related dermatoses, inherited epidermolysis bullosa variants, Hailey-Hailey disease, and porphyria cutanea tarda. Other conditions manifest microscopic acantholysis within the surface epithelium but are not associated with clinical bullae, such as Darier disease and Grover disease. Finally, both infectious and non-infectious causes exist for the development of neutrophilic pustules in the epidermis, as seen in pustular psoriasis, Sneddon-Wilkinson disease (subcorneal pustular dermatosis), and acute generalized exanthematous pustulosis. This review considers the clinical and histological features of all of these diseases.

Subcorneal Pustular Dermatosis: A Review of 30 Years of Progress

Subcorneal pustular dermatosis (SPD), also known as Sneddon-Wilkinson disease, is a rare, benign yet relapsing pustular dermatosis. Its incidence and prevalence have not been well studied. It characteristically presents as hypopyon pustules on the trunk and intertriginous areas of the body. SPD is similar to two other disease entities. Both SPD-type immunoglobulin (Ig)-A pemphigus and annular pustular psoriasis clinically and histologically present similarly to SPD. Immunologic studies separate SPD-type IgA pemphigus from SPD and pustular psoriasis. However, there is still an unclear designation as to whether SPD is its own entity distinct from pustular psoriasis, as the once thought characteristic histologic picture of psoriasis does not hold true for pustular psoriasis. SPD has been reported to occur in association with several neoplastic, immunologic, and inflammatory conditions. Dapsone remains the first-line treatment for SPD, although dapsone-resistant cases have been increasingly reported. Other therapies have been used singly or as adjunctive therapy with success, such as corticosteroids, immunosuppressive agents, tumor necrosis factor inhibitors, and ultraviolet light therapy. This article provides a review of the last 30 years of available literature, with a focus on successful treatment options and a suggestion for reappraisal of the classification of SPD.

Ofuji disease: a rare dermatosis and its challenging therapeutic approach

Eosinophilic pustular folliculitis (EPF) or Ofuji disease is a rare dermatosis, prone to recurrence and chronicity. The peak incidence occurs in the third decade of life and its exact etiology remains unknown. Evidence suggests that the expression of adhesion molecules and the production of cytokines activate the follicular unit, but the stimulus that triggers these changes remains unclear. The three clinical variants reported in the literature include classic EPF, immunosuppression-associated EPF, and infancy-associated EPF. We report a case of eosinophilic pustular folliculitis with peculiar epidemiological characteristics, which represents a challenging therapeutic scenario.

Acute generalized exanthematous pustulosis x Von Zumbusch's pustular psoriasis: a diagnostic challenge in a psoriatic patient

Severe cutaneous drug reactions include a wide spectrum of clinical manifestations ranging from mild morbilliform cutaneous rash, to severe forms of hypersensitivity. Special attention is given in this report to the acute generalized exanthematous pustulosis (AGEP), induced in 90% of cases by the use of systemic drugs, especially aminopenicillins and macrolides. The incidence of the disease is low, 1-5 cases per million patients / year. The main differential diagnosis is Von Zumbusch's Pustular Psoriasis. The prognosis is generally good and the disease self limited, after withdrawal of the triggering drug. In this report the authors describe a case of AGEP, triggered by ceftriaxone in a patient with psoriasis vulgaris.

Neutrophilic dermatoses: an update

Neutrophilic dermatoses constitute a heterogeneous group of dermatologic diseases, which are unified by the predominance of neutrophils within the inflammatory infiltrate on histopathology. The aims of this review were to provide an update on the clinical and histologic presentation of the main neutrophilic dermatoses and to develop a guide for clinical practice. A structured literature search of PubMed, Medline, and Embase was performed, using the key words "neutrophilic disorders", "cutaneous small vessel vasculitis", "Sweet's syndrome", "bowel associated dermatosis arthritis syndrome", "Behcet's", "palisaded neutrophilic and granulomatous dermatosis", "rheumatoid neutrophilic dermatitis", and "pyoderma gangrenosum". Related articles were screened for key terms and were included if appropriate. This group contains a wide spectrum of unique disorders, each with its own histologic and clinical subtleties, making specific diagnosis of a given entity within the group diagnostically challenging. The fact that overlapping forms of neutrophilic dermatoses, which share features of multiple neutrophilic dermatoses, are not uncommon makes the diagnoses more challenging.

Nail psoriasis: a review of the literature

Nails are considered epidermal appendages, and as such, are commonly affected in patients with psoriasis, 80% of whom are likely to develop nail psoriasis as a result of their condition. Two patterns of nail disorders have been shown to be caused by psoriasis. Nail matrix involvement can result in features such as leukonychia, pitting (punctures or cupuliform depressions), red spots in the lunula and crumbling. Nail bed involvement, on the other hand, can cause onycholysis, salmon or oil-drop patches, subungual hyperkeratosis and splinter hemorrhages. Nail disease causes aesthetic and functional impairment, and is indicative of more severe forms of psoriasis as well as of joint involvement. The treatment for nail psoriasis involves behavioral interventions, topical medications, or systemic therapy in case of extensive skin or joint involvement. This article presents a review of the main features of nail psoriasis, its clinical presentation, diagnostic and assessment methods, clinical repercussions, and of its available treatment options.