Reactive granulomatous dermatitis as a histological pattern including manifestations of interstitial granulomatous dermatitis and palisaded neutrophilic and granulomatous dermatitis: a study of 52 patients

BACKGROUND

Confusion exists regarding interstitial granulomatous dermatitis (IGD) and palisaded neutrophilic and granulomatous dermatitis (PNGD).

OBJECTIVE

To determine whether IGD and PNGD are two different entities, or whether they must be considered as two subtypes of the same reactive pattern, and thus whether the unification of the nomenclature is necessary.

METHODS

Observational retrospective multicentre study of patients with IGD and PNGD evaluated between 1999 and 2019 and review of their clinical and histological features.

RESULTS

We identified 52 patients (38 women and 14 men). Clinical and histological findings of IGD were observed in 88.4% of cases. The most common cutaneous lesions were plaques/macules (IGD) or annular plaques and papules/nodules (PNGD), located mostly on the limbs and trunk. The rope sign was developed in two patients with IGD that associated autoimmune disorders. Similar associated comorbidities (75%) were found in both entities, mainly autoimmune diseases (53.8%). In IGD, the infiltrate was predominantly lympho-histiocytic. Neutrophilic infiltrates, karyorrhexis and skin lesions with limited clinical course were mainly associated with PNGD biopsies. In biopsies with a limited recurrent course, a predominant lymphocytic inflammatory infiltrate was found. Collagen degeneration was present in 75.9% of cases. The floating sign was observed only in IGD type patients (63%). Overlapping histological findings were found in one fourth of cases, especially between IGD and interstitial granuloma annulare. Interface dermatitis, apparently unrelated to drug intake, was observed in 4 cases of IGD.

CONCLUSION

We support the term reactive granulomatous dermatitis to unify both the clinical and histological findings of IGD and PNGD, and the overlapping between IGD and interstitial granuloma annulare. According to this, a spectrum of histological changes will be found depending on the clinical course of the skin lesions.

The involvement of ADAM10 in acantholysis in mucocutaneous pemphigus vulgaris depends on the autoantibody profile of each patient

BACKGROUND

Acantholysis in pemphigus vulgaris (PV) may be triggered by desmoglein (Dsg) and non-Dsg autoantibodies. The autoantibody profile of each patient results in distinct intracellular signalling patterns.

OBJECTIVES

Based on our previous findings, we aimed to elucidate whether PV acantholysis in a mouse model may be mediated by activation of a disintegrin and metalloproteinase 10 (ADAM10).

METHODS

We used three PV-IgG fractions from different patients containing high or low levels of anti-Dsg1 and anti-Dsg3 antibodies, and the presence or not of anti-desmocollin (Dsc) antibodies, using a passive transfer mouse model of PV.

RESULTS

Although all of the PV-IgG fractions produced suprabasal acantholysis, only those containing anti-Dsg1/3, but not anti-Dsc2/3 antibodies, induced ADAM10 activation in a Src-dependent way, and an increase in the epidermal growth factor (EGF) receptor ligands EGF and betacellulin (BTC). In contrast, the presence of anti-Dsc2/3 antibodies, in addition to anti-Dsg1/3, triggered earlier and ADAM10-independent epidermal detachment, with no increase in EGF and BTC, which was associated with an earlier and more intense acantholysis.

CONCLUSIONS

All PV-IgG fractions produced suprabasal acantholysis, but our results reveal that depending on the levels of anti-Dsg antibodies or the presence of non-Dsg antibodies, such as anti-Dsc, more severe cell-cell epidermal detachment will occur at different times, and in an ADAM10-dependent manner or not. Acantholysis in these different groups of patients with PV may be a consequence of the activation of specific intracellular mechanisms downstream of Autoantibodies binding to Dsg or non-Dsg proteins, and therefore more specific therapeutic approaches in PV should be used. What's already known about this topic? Suprabasal acantholysis in pemphigus vulgaris (PV) may be triggered by both desmoglein (Dsg) and non-Dsg autoantibodies. The autoantibody profile of each patient is associated with a distinct intracellular signalling pattern. What does this study add? In patients with PV with anti-Dsg3 and anti-Dsg1, but not anti-desmocollin (Dsc)3 antibodies, ADAM10 activation is induced in an Src-dependent way, together with an increase in the epidermal growth factor receptor (EGFR) ligands EGF and betacellulin. The presence of anti-Dsc3 antibodies triggers an earlier and ADAM10-independent acantholysis, without increasing EGFR ligands, and is associated with more severe epidermal detachment. Lower levels of anti-Dsc3 antibodies are associated with less severe acantholysis. What is the translational message? In some patients with PV, the severity and the timing for cell-cell detachment seem to depend on the level of anti-Dsg1/3 antibodies, although other as yet uncharacterized antibodies may also participate. These patients with PV would exhibit inhibition of acantholysis by Src, ADAM10, EGF and EGFR inhibitors. In other patients, the presence of non-Dsg antibodies, such as anti-Dsc2/3, would produce an earlier and more severe ADAM10-independent suprabasal acantholysis.

Clinical management of cutaneous adverse events in patients on targeted anticancer therapies and immunotherapies: a national consensus statement by the Spanish Academy of Dermatology and Venereology and the Spanish Society of Medical Oncology

Progress in the understanding of many tumors has enabled the development of new therapies, such as those targeted at specific molecules involved in cell growth (targeted therapies) or intended to modulate the immune system (immunotherapy). However, along with the clinical benefit provided by these new treatments, new adverse effects have also appeared. Dermatological toxicities such as papulopustular eruptions, xerosis, and pruritus are common with EGFR inhibitors. Other adverse effects have also been described with PDGFR, BCR-ABL, and MAPK tyrosine kinase inhibitors, antiangiogenic drugs, and inhibitors at immune checkpoints such as CTLA-4 and PD-1/PD-L1. Onset of these adverse effects often causes dose reductions and/or delays in administering the prescribed therapy, which can affect patient survival and quality of life. It is, therefore, important to prevent the occurrence of these adverse effects, or to treat unavoidable ones as soon as possible. This requires cooperation between medical oncologists and dermatologists. This article reviews the various dermatological toxicities associated with targeted therapies and immunotherapies, along with their diagnosis and therapeutic management.

Exploring beyond the oral mucosa in patients affected with autoimmune blistering diseases: the importance of endoscopic procedures

Autoimmune blistering diseases (AIBD) comprise several entities characterized by the presence of autoantibodies targeted against structural proteins either in desmosomes or in the dermoepidermal junction of polystratified squamous epithelium. Patients develop blisters, erosions in cutaneous surfaces or mucosas. Diagnosis is based on the characteristic mucocutaneous lesions, the typical findings on histological studies and direct immunofluorescence assays, and the presence of specific autoantibodies against the epidermal antigens. It may not be possible for dermatologists to appropriately explore the nose and throat (NT). Thus, a clinical exploration by endoscopic procedures of NT may be a useful tool during the conventional dermatological exam. The aims of this review are to draw attention to the most frequent NT manifestations in AIBD patients, and underline the utility of endoscopic procedures to achieve a more successful and rationale management of patients. Additionally, we will provide brief information related to the anatomical structures and type of epithelium in NT areas which may explain the extent and type of NT involvement in AIBD. Endoscopic exploration in AIBD patients is important for several reasons. Firstly, it will allow the real NT mucosal involvement in each patient to be determined, thus making a differential diagnosis during the endoscopic exam possible, based on the localization of mucosal lesions. Secondary mucosal morbidity can also be ruled out. Secondly, the clinical response to treatment may be established, especially in NT mucosa, as these are anatomical areas subjected to important local traumas, and physiological functions such as breathing, swallowing, speech production and phonation may be damaged. Therefore, a multidisciplinary management in AIBD is mandatory by both dermatologists and otorhinolaryngologists, adding the clinical exploration by endoscopic procedures of NT to the conventional dermatological exam in all AIBD patients, irrespective of whether they exhibit associated symptoms.

Rituximab in dermatology

Rituximab was introduced into clinical practice as a medication with considerable potential. Its use in patients with B-cell lymphoma and rheumatoid arthritis revealed numerous indications in autoimmune diseases, many of which involve the skin, thus requiring dermatologists to become familiar with both the characteristics of anti-CD20 antibodies and the role of B cells in multiple skin diseases. Thanks to these developments, we will be able to use rituximab more frequently and appropriately in our patients and draw up consensus guidelines based on large case series. In other words, establishing the indications for rituximab will make it possible to shorten disease course and reduce morbidity due to more specific drugs.

Study of oral, ear, nose and throat involvement in pemphigus vulgaris by endoscopic examination

BACKGROUND

Pemphigus vulgaris (PV) is an autoimmune blistering skin disorder characterized by the presence of suprabasal acantholysis and autoantibodies against desmoglein 3. There are two different clinical forms: mucocutaneous (MCPV) and mucosal (MPV). However, little is known about PV lesions in oral, ear, nose and throat (OENT) areas produced by the very dynamic of the anatomical structures involved in the functions of the aerodigestive tract.

OBJECTIVES

To investigate the pattern of OENT manifestations in PV, and their relationship with physiological traumatic mechanisms in stratified squamous epithelial structures.

METHODS

A prospective analysis of 40 patients diagnosed with MCPV (22 patients) or MPV (18 patients) was carried out at the University Clinic of Navarra. OENT manifestations were evaluated in all patients endoscopically. OENT involvement was divided into anatomical areas.

RESULTS

The most frequent symptom was pain, mainly on oral mucosa (87·5%). Buccal mucosa (90%), posterior wall of pharynx (67·5%), upper edge of epiglottis (85%) and nasal vestibule (70%) were the areas most frequently affected in the OENT mucosa. These localizations were related to physiological traumatic mechanisms in polystratified squamous epithelial structures.

CONCLUSIONS

OENT endoscopy should be included in the examination of all patients with PV. Knowledge of the most frequent localizations of active lesions on OENT mucosa in PV will help us to interpret more efficiently the findings from OENT endoscopy. Also, information related to traumatic physiological mechanisms on OENT areas must be offered to patients in order to avoid the appearance of new active PV lesions.

Subsequent nonmelanoma skin cancer after liver transplantation

BACKGROUND

Liver transplant recipients have a high risk of developing nonmelanoma skin cancer (NMSC). Some develop multiple NMSC.

METHODS

Patients with a follow-up of >1 year have been prospectively followed to detect NMSC. We studied the risk of developing >1 NMSC.

RESULTS

After a follow-up of 2658 patient-years (mean, 8.5 years per patient), 59/312 (19%) patients were diagnosed with NMSC. Twenty-five had >1 NMSC. The 5-year risk of developing 1 NMSC, >1 NMSC, and a subsequent NMSC (a new NMSC after a first one) were 15%, 5.5%, and 46.5%, respectively. Age >60 years and transplantation for hepatocellular carcinoma were independently associated with a higher risk of developing >1 NMSC.

CONCLUSION

NMSC are frequent complications after liver transplantation and they may show a high rate of recurrence. Older age and hepatocellular carcinoma were related to the development of multiple NMSC.