Characterization and Management of Amicrobial Pustulosis of the Folds, Aseptic Abscess Syndrome, Behçet Disease, Neutrophilic Eccrine Hidradenitis, and Pyostomatitis Vegetans-Pyodermatitis Vegetans.

Neutrophilic dermatoses are a broadly heterogeneous group of inflammatory skin disorders. This article reviews 5 conditions: amicrobial pustulosis of the folds, aseptic abscess syndrome, Behçet disease, neutrophilic eccrine hidradenitis, and pyostomatitis vegetans-pyodermatitis vegetans.The authors include up-to-date information about their epidemiology, pathogenesis, clinicopathologic features, diagnosis, and management.

Clinical and Histopathologic Spectrum of Toxic Erythema of Chemotherapy: A Series of 56 Cases From a Single Institution.

INTRODUCTION: Although many individual cases and small series of toxic erythema of chemotherapy (TEC) have been described, the full spectrum of findings is not well understood. OBJECTIVE: To provide a comprehensive review of the clinical and histopathologic features of TEC with an emphasis on novel histopathologic findings. METHODS: We searched our electronic medical record for "toxic erythema of chemotherapy" or "neutrophilic eccrine hidradenitis." Fifty-six cases meeting clinical and histopathologic criteria were identified. The electronic medical record and accompanying hematoxylin and eosin-stained slides were retrospectively reviewed. RESULTS: The clinical findings were heterogeneous but included classic presentations such as intertriginous eruptions (34%) and acral erythema (25%). The most common histopathologic features were apoptotic keratinocytes (95%), basal vacuolar change (91%), and epithelial dysmaturation (79%). Eccrine squamous syringometaplasia was seen in over half of the cases (33/56; 59%), whereas neutrophilic eccrine hidradenitis was uncommon (16%). Interestingly, many cases showed prominent interstitial histiocytes (55%). Other novel findings included irregular orthohyperkeratosis (23%), irregular epidermal hyperplasia (14%), and acantholysis (9%). LIMITATIONS: As a retrospective study, it is subject to information bias. CONCLUSION: This is the largest reported series of TEC. In addition to confirming previously reported features, we identify novel histopathologic findings to add to the spectrum of TEC.

Neutrophilic eccrine hidradenitis: a retrospective study.

BACKGROUND: Neutrophilic eccrine hidradenitis (NEH) is a benign neutrophilic dermatosis not well recognized beyond an association with malignancy. Although the disease is commonly reported in adults with malignancy, this association is uncommon in children. The diagnosis of NEH is predominantly based on histologic findings to exclude alternative diagnoses for adults, but biopsy is not usually required for children. METHODS: A retrospective study was performed of adult and pediatric patients diagnosed with NEH at three Mayo Clinic sites from January 1, 1992, to January 1, 2022. The aim of this study was to elucidate risk factors for NEH and its clinical characteristics, treatment options, and natural course. Clinical information and pathologic results were collected from health records. Available pathologic slides were reviewed with a dermatopathologist. RESULTS: Of 47 patients identified, 33 had either histologic or clinical confirmation of the diagnosis; 21 were adults (64%), and 12 were children (36%). Most adults (16/21; 76%) had underlying malignancy and received chemotherapy. Five adults (24%) were classified as having idiopathic NEH, and they were younger and had higher NEH recurrence rates than the other adults. Only one pediatric patient (8%) had underlying malignancy. For 10 children (83%), NEH was preceded by strenuous activity. Initial findings of idiopathic NEH were palmoplantar eruptions for both adult and pediatric patients, whereas malignancy-associated NEH commonly involved the face and axillae. CONCLUSIONS: Among adults, NEH is commonly associated with malignancy and chemotherapy. Among children, idiopathic NEH occurs primarily after overexertion, and malignancy is highly unlikely to be the cause of NEH.

Infectious eccrine hidradenitis: sweat glands as the portal of entry for cellulitis.

Neutrophilic eccrine hidradenitis (NEH) is a rare neutrophilic dermatosis involving the eccrine glands. It is commonly associated with haematological malignancy and administration of chemotherapy. An infective aetiology for NEH is termed infectious eccrine hidradenitis (IEH). Pathogens that have been associated with IEH include Nocardia, Serratia, Enterobacter sp., Staphylococcus aureus and Mycobacterium chelonae We describe a case of IEH in a patient with prolonged use of a compression sleeve for their upper limb lymphoedema. The histopathological findings of NEH and IEH are almost identical. Skin tissue culture and rapid clinical improvement with antibiotic therapy are keys in delineating the two subtypes.

Acute acral eruptions in children during the COVID-19 pandemic: Characteristics of 103 children and their family clusters.

BACKGROUND: A marked increase in frequency of acute acral eruptions (AAE) was observed in children during the COVID-19 pandemic in the spring period. OBJECTIVES: In this observational multicenter study, based on children with AAE, we aimed to assess the proportion of household members possibly infected by SARS-CoV-2. METHODS: We collected data from all children observed with AAE, prospectively from April 7, 2020 to June 22, 2020, and retrospectively since February 28, 2020. The primary outcome was the household infection rate, defined as the proportion of family clusters having at least one member with COVID-19 infection other than the child with AAE ("index child"). The definition of a case was based on characteristic clinical signs and a positive PCR or serology. RESULTS: The study included 103 children in 10 French departments and in Quebec. The median age was 13 years and the interquartile range [8-15], with a female-to-male ratio of 1/1.15. In children with AAE, all PCR tests were negative (n=18), and serology was positive in 2/14 (14.3%) cases. We found no significant anomalies in the lab results. A total of 66 of the 103 families (64.1%) of included children had at least one other infected member apart from the index child. The total number of household members was 292, of whom 119 (40.8%) were considered possibly infected by SARS-CoV-2. No index children or households exhibited severe COVID-19. DISCUSSION: Among the 103 households included, 64.1% had at least one infected member. Neither children with AAE nor their households showed severe COVID-19.

[Painful nodules on the soles in a pediatric patient: A diagnostic challenge]. / Nodulos plantares dolorosos tras ejercicio intenso en paciente pediátrica: Un reto diagnóstico.

INTRODUCTION: Idiopathic Palmoplantar Eccrine Hidradenitis (IPPH) is a rare neutrophilic derma tosis, with painful erythematous nodules of sudden onset in the plantar or palmoplantar region, in children without other underlying diseases. OBJECTIVE: To present a case that shows the main clinical and histological characteristics of this entity. CLINICAL CASE: 11-year-old girl with a 48-hours history of painful erythematous-violaceous nodules on the right foot plant associated with fever of up to 38.2 °C, with no history of interest except hyperhidrosis and intense exercising on previous days. Given the clinical suspicion of IPPH, a skin biopsy was performed, which showed inflammatory neutrophil infiltration around eccrine sweat glands and neutrophilic abscesses, confirming the diagnosis. Oral NSAIDs and rest were prescribed, with resolution of the lesions in 7 days. CONCLUSIONS: This case demonstrates the most important aspects of this entity, in many cases underdiagnosed, since it can be confused with other pathologies that occur with painful acral nodules, but have different pathogenic and therapeutic implications. To properly identify the IPPH allows preventing an unnecessary alarm, both patients and their parents, as in dermatologists and pediatricians themselves.

Nodulos plantares dolorosos tras ejercicio intenso en paciente pediátrica: un reto diagnóstico / Painful nodules on the soles in a pediatric patient: a diagnostic challenge

Resumen: Introducción: La Hidradenitis palmoplantar ecrina idiopática (HPPI) es una dermatosis neutrofílica infrecuente, que cursa con nódulos eritematosos dolorosos de comienzo brusco en regiones plantares o palmoplantares, en niños que no tienen otra enfermedad subyacente. Objetivo: Presentar un caso que ilustra las principales características clínicas e histológicas de la HPPI. Caso Clínico: Niña de 11 años evaluada por nódulos eritematovioláceos dolorosos en planta de pie derecho de 48 horas de evo lución y fiebre de hasta 38,2 °C, sin antecedentes de interés salvo hiperhidrosis y práctica intensa de ejercicio en los días previos. Ante la sospecha clínica de HPPI se realizó biopsia cutánea, que mostró infiltrado inflamatorio neutrofílico alrededor de glándulas sudoríparas ecrinas y abscesos de neutrófilos, confirmando el diagnóstico. Se indicaron antiinflamatorios no esteroidales orales y reposo, con resolución de las lesiones en 7 días. Conclusiones: Este caso demuestra los aspectos más importantes de la HPPI. Esta entidad en muchos casos es infradiagnosticada, dado que puede confundirse con otras patologías que también cursan con nódulos acrales dolorosos, pero tienen distintas implicacio nes patogénicas y terapéuticas. Identificar apropiadamente la HPPI permite evitar la alarma innece saria, tanto en pacientes y sus padres, como en los propios dermatólogos y pediatras.

Abstract: Introduction: Idiopathic Palmoplantar Eccrine Hidradenitis (IPPH) is a rare neutrophilic derma tosis, with painful erythematous nodules of sudden onset in the plantar or palmoplantar region, in children without other underlying diseases. Objective: To present a case that shows the main clinical and histological characteristics of this entity. Clinical Case: 11-year-old girl with a 48-hours history of painful erythematous-violaceous nodules on the right foot plant associated with fever of up to 38.2 °C, with no history of interest except hyperhidrosis and intense exercising on previous days. Given the clinical suspicion of IPPH, a skin biopsy was performed, which showed inflammatory neutrophil infiltration around eccrine sweat glands and neutrophilic abscesses, confirming the diagnosis. Oral NSAIDs and rest were prescribed, with resolution of the lesions in 7 days. Conclusions: This case demonstrates the most important aspects of this entity, in many cases underdiagnosed, since it can be confused with other pathologies that occur with painful acral nodules, but have different pathogenic and therapeutic implications. To properly identify the IPPH allows preventing an unnecessary alarm, both patients and their parents, as in dermatologists and pediatricians themselves.

[Case Report of Pseudomonas Hot-Foot Syndrome in Uppsala, Sweden]. / Badhusfötter ­ ny diagnos i Sverige.

During February and March 2019, an accumulation of clinically similar erythematous plantar nodules was observed at the University Children's Hospital and several primary care facilities in Uppsala, Sweden. At least 20 children sought medical advice, and all cases presented with a recurrent plantar hidradenitis after within a day after visiting Uppsala's largest waterpark and arena for swimming. The presented symptoms were identical with a condition called pseudomonas hot-foot syndrome described in the literature. An investigation led by the local public health authorities revealed heavy growth of Pseudomonas aeruginosa in water-filled toys in a children's play area and in samples taken from the floor of a pool where the surface was partly damaged. After closing the affected part of the pool and removal of the contaminated toys, no more people sought medical advice. Pseudomonas hot-foot syndrome is believed to be more frequent than diagnosed today, and increased awareness is essential to avoid unwarranted diagnostic tests and treatments, and to identify and eradicate the source of infection.

Neutrophilic dermatoses: Pathogenesis, Sweet syndrome, neutrophilic eccrine hidradenitis, and Behçet disease.

Neutrophilic dermatoses are a heterogeneous group of inflammatory skin disorders that present with unique clinical features but are unified by the presence of a sterile, predominantly neutrophilic infiltrate on histopathology. The morphology of cutaneous lesions associated with these disorders is heterogeneous, which renders diagnosis challenging. Moreover, a thorough evaluation is required to exclude diseases that mimic these disorders and to diagnose potential associated infectious, inflammatory, and neoplastic processes. While some neutrophilic dermatoses may resolve spontaneously, most require treatment to achieve remission. Delays in diagnosis and treatment can lead to significant patient morbidity and even mortality. Therapeutic modalities range from systemic corticosteroids to novel biologic agents, and the treatment literature is rapidly expanding. The first article in this continuing medical education series explores the pathogenesis of neutrophilic dermatoses and reviews the epidemiology, clinical and histopathologic features, diagnosis, and management of Sweet syndrome, neutrophilic eccrine hidradenitis, and Behçet disease.

Lymphocytic hidradenitis: A distinctive histopathological finding of annular erythema of Sjögren syndrome.

BACKGROUND/OBJECTIVES: Lymphocytic hidradenitis is a non-specific histopathological feature observed in many dermatoses such as lupus erythematosus, morphea or scleroderma. When it occurs it is usually accompanied by the other distinctive histological features of those conditions. Isolated lymphocytic hidradenitis is uncommon and its clinical features and associated underlying medical conditions are still undetermined. METHODS: We performed a retrospective review of patients who clinically presented with annular erythema between 2000 and 2016. Altogether, 30 patients with a histopathological presentation of isolated lymphocytic hidradenitis were identified. Their following characteristics were recorded: clinical features, number and localisation of lesions, serology and other associated medical conditions. RESULTS: Isolated lymphocytic hidradenitis was found most frequently in middle-aged women. Most patients (n = 28, 93%) presented with many annular erythematous patches and plaques with mild pruritus; 22 (73%) had the SS-A antibody and 17 (57%) met the diagnostic criteria of Sjögren syndrome. Among these patients, 11 had primary and six had secondary Sjögren syndrome associated with systemic lupus erythematosus. Altogether 15 (50%) patients tested positive for a high titre of the antinuclear autoantibody. Other underlying diseases identified during the follow-up period include cryoglobulinaemia, angioimmunoblastic T-cell lymphoma, autoimmune hepatitis, hepatitis C infection and toxic thyroid goitre. CONCLUSIONS: Lymphocytic hidradenitis is a microscopic finding associated with annular erythemas of Sjögren syndrome. Systemic survey for sicca symptoms and work up for autoimmune diseases, including antinuclear antibodies, SS-A, SS-B antibodies, cryoglobulin, lymphoma, viral and autoimmune hepatitis should be performed to facilitate the correct diagnosis.

Neutrophilic Eccrine Hidradenitis in an HIV-Infected Patient.

A 35-year-old man presented with a 2-day history of a maculopapular pruritic eruption that had affected his general state of health and was accompanied by chills. The patient had been diagnosed with HIV in 2008, and was undergoing treatment with a combination of emcitrabine/tenofovir plus nevirapine. He had a current viral load of 1,558,160 copies/mL and a lymphocyte count CD4+ count of 230/mm3. Physical examination revealed an eruption involving the face, nape of the neck, chest, abdomen, extremities, palms, and soles. This was characterized by erythematous papules approximately 2 mm in diameter coalescing on the palms and soles, where they formed plaques (Figures 1 and 2).