Ana Gameiro

HLA-B*58:01 is a risk factor for allopurinol-induced DRESS and Stevens–Johnson syndrome/toxic epidermal necrolysis in a Portuguese population

HLA‐B*58:01 is associated with allopurinol‐induced severe cutaneous adverse drug reactions (sCADR) particularly in Han Chinese, but the risk in European populations has seldom been studied.

Pyoderma gangrenosum: challenges and solutions

Pyoderma gangrenosum (PG) is a rare disease, but commonly related to important morbidity. PG was first assumed to be infectious, but is now considered an inflammatory neutrophilic disease, often associated with autoimmunity, and with chronic inflammatory and neoplastic diseases. Currently, many aspects of the underlying pathophysiology are not well understood, and etiology still remains unknown. PG presents as painful, single or multiple lesions, with several clinical variants, in different locations, with a non specific histology, which makes the diagnosis challenging and often delayed. In the classic ulcerative variant, characterized by ulcers with inflammatory undermined borders, a broad differential diagnosis of malignancy, infection, and vasculitis needs to be considered, making PG a diagnosis of exclusion. Moreover, there are no definitively accepted diagnostic criteria. Treatment is also challenging since, due to its rarity, clinical trials are difficult to perform, and consequently, there is no “gold standard” therapy. Patients frequently require aggressive immunosuppression, often in multidrug regimens that are not standardized. We reviewed the clinical challenges of PG in order to find helpful clues to improve diagnostic accuracy and the treatment options, namely topical care, systemic drugs, and the new emerging therapies that may reduce morbidity.

Methylisothiazolinone: second ‘epidemic’ of isothiazolinone sensitization

Isothiazolinones are used as biocides in a wide variety of products, such as cosmetics, detergents, and industrial products. In the 1980s, a formulation with methylchloroisothiazolinone (MCI) and methylisothiazolinone (MI) was responsible for an allergic contact dermatitis ‘epidemic’. To control this phenomenon, a maximum allowed dose was set. However in 2005, MI alone was introduced in cosmetics, and this was followed by a new ‘epidemic’ of sensitization to MI and MCI/MI (1). We performed a retrospective study, consulting the medical files of patch tested patients reactive to ISs, from 2005 to 2013. MCI/MI was tested at 100 ppm in water (TROLAB® patch test allergens, Almirall Hermal

Benign follicular tumors

Benign follicular tumors comprise a large and heterogeneous group of neoplasms that share a common histogenesis and display morphological features resembling one or several portions of the normal hair follicle, or recapitulate part of its embryological development. Most cases present it as clinically nondescript single lesions and essentially of dermatological relevance. Occasionally, however, these lesions be multiple and represent a cutaneous marker of complex syndromes associated with an increased risk of visceral neoplasms. In this article, the authors present the microscopic structure of the normal hair follicle as a basis to understand the type and level of differentiation of the various follicular tumors. The main clinicopathological features and differential diagnosis of benign follicular tumors are then discussed, including dilated pore of Winer, pilar sheath acanthoma, trichoadenoma, trichilemmoma, infundibuloma, proliferating trichilemmal cyst/tumor, trichoblastoma and its variants, pilomatricoma, trichodiscoma/fibrofolliculoma, neurofollicular hamartoma and trichofolliculoma. In addition, the main syndromes presenting with multiple follicular tumors are also discussed, namely Cowden, Birt-Hogg-Dubé, Rombo and Bazex-Dupré-Christol syndromes, as well as multiple tumors of follicular infundibulum (infundibulomatosis) and multiple trichoepitheliomas. Although the diagnosis of follicular tumors relies on histological examination, we highlight the importance of their knowledge for the clinician, especially when in presence of patients with multiple lesions that may be the cutaneous marker of a cancer-prone syndrome. The dermatologist is therefore in a privileged position to recognize these lesions, which is extremely important to provide further propedeutic, appropriate referral and genetic counseling for these patients.

Long-term management of chronic spontaneous urticaria with omalizumab

Clinical trials have shown the efficacy of omalizumabs efficacy in refractory chronic spontaneous urticaria (CSU) and chronic inducible urticaria (CIndU), but real‐life management strategies are lacking.

Overlap between maculopapular exanthema and drug reaction with eosinophilia and systemic symptoms among cutaneous adverse drug reactions in a dermatology ward.

Inpatients with cutaneous adverse drug reactions (CADR) with overlapping features between maculopapular exanthema (MPE) and drug reaction with eosinophilia and systemic symptoms (DRESS) were examined.

Mycobacterium chelonae Is an Ubiquitous Atypical Mycobacterium.

The type of cutaneous infection varies mainly according to the patients immune status, and the disseminated form is mostly found in the context of immunosuppression. We report the case of a 62-year-old male who was under long-term systemic corticosteroid therapy and presented with a 7-month history of multiple painless cutaneous lesions at various stages of development: papules, nodules, pustules and hemorrhagic crusts, as well as small erosions and ulcers distributed over the limbs and scalp. Cutaneous biopsy showed a suppurative granulomatous infiltrate with abscess formation. Fite stain revealed numerous extracellular bacilli, suggesting mycobacterial infection, particularly by atypical mycobacteria. Culture of a skin sample revealed Mycobacterium chelonae. The patient started multidrug therapy and showed clinical improvement despite of resistance to one of the antibiotics. This striking presentation underlines the role of immunosuppression with corticotherapy as a major risk factor for these infections. Multidrug therapy is advised and antibiogram is essential in directing treatment.

Histopathology of the Exanthema in DRESS Is Not Specific but May Indicate Severity of Systemic Involvement.

Objective:Exanthema in drug reaction with eosinophilia and systemic symptoms (DRESS) has no specific clinical diagnostic hallmark and there are few histopathologic studies. The aim of this study was to describe dermal–epidermal histopathologic features in DRESS and correlate them with the culprit drug, viral reactivation, or systemic organ involvement. Methods:Skin biopsies were independently evaluated by 2 dermatopathologists who characterized the main histological patterns and scored dermal and epidermal changes, which were further correlated with clinical and laboratorial data. Results:In 15 DRESS patients (9 male/6 female patients, mean age 53.3 years), the main observation was lymphocyte exocytosis (1.87 ± 1.25), spongiosis (0.93 ± 0.94), scattered keratinocyte necrosis (1.70 ± 1.44), basal cell vacuolization (2.13 ± 1.42), lymphocyte infiltration around dermal vessels (2.93 ± 0.92) or at the dermal–epidermal junction (2.07 ± 1.12), often with eosinophils and extravasated erythrocytes, swollen endothelial cells, and intravascular neutrophils but no vasculitis. Histopathologic patterns were classified mainly as spongiotic (5), erythema multiforme-like (3), or lichenoid (2). There was a significant positive correlation between the intensity of lymphocyte infiltration and the severity of hepatic cytolysis (r = 0.51; P < 0.05) and eosinophilia (r = 0.51; P < 0.05). No correlation was observed between the intensity and type of dermal inflammation and the degree of epidermal damage or the culprit drug. Human herpes virus type 6–positive patients had a pseudolymphomatous reaction or a perifollicular localization of the infiltrate. Conclusions:Histopathology in DRESS is variable with no specific diagnostic aspect, but there is a possible correlation between the intensity of the lymphocyte infiltrate and DRESS severity, namely, liver cytolysis.

Clinical characterization and long-term follow-up of Schnitzler syndrome

Schnitzler syndrome (SchS) is an acquired autoinflammatory disease characterized by chronic urticarial rash in association with monoclonal gammopathy. Patients may progress to lymphoproliferative disorders, but the associated factors and exact risk of progression are still not well defined.

Histological variability and the importance of clinicopathological correlation in cutaneous Rosai-Dorfman disease

Rosai-Dorfman disease is a benign histiocytic proliferative disorder of unknown etiology. The disease mainly affects lymph node tissue, although it is rarely confined to the skin. Here, we describe a 53-year-old woman with purely cutaneous Rosai-Dorfman disease. The patient presented with a large pigmented plaque on her left leg, and sparse erythematous papules on her face and arms. A complete clinical response was achieved with thalidomide, followed by recurrence at the initial site one year later. The histological examination displayed the typical features of Rosai-Dorfman disease in the recent lesions but not in the older lesions. In the setting of no lymphadenopathy, the histopathological features of Rosai-Dorfman disease are commonly misinterpreted. Therefore, awareness of the histological aspects present at different stages, not always featuring the hallmark microscopic signs of Rosai-Dorfman disease, is particularly important for a correct diagnosis of this rare disorder.