Concomitant granuloma annulare and necrobiosis lipoidica: do they have a related pathogenesis?

Granuloma annulare and necrobiosis lipoidica in a patient with HNF1A-MODY

Maturity-onset diabetes of the young (MODY) is a heterogeneous group of monogenic forms of diabetes mellitus with distinct clinical features. Clinical dermatological phenotypes in MODY patients are very rare in literature. This report describes a patient with HNF1A-MODY presenting with necrobiosis lipoidica (NL) and granuloma annulare (GA). A 39-year-old asymptomatic woman, with atypical diabetes diagnosed at age 17, has a confirmed HNF1A mutation on exon 2 (c.392G>A, p.R131Q), classified as Pathogenic by the ACMG guidelines. She has reasonable metabolic control using oral anti-diabetic medications and has no chronic diabetic complications. Clinical and histologic diagnoses of both NL and GA were made. We discuss these conditions and their association with MODY.

Skin Involvement in Paediatric Patients with Type 1 Diabetes

Skin involvement is an overlooked aspect in the management of paediatric patients with type 1 diabetes. A comprehensive search of published literature using the PubMed database was carried out using the following key terms: "children," "pediatric/paediatric patients," "skin," "skin disorders," "type 1 diabetes." Dermatological side effects are frequently observed among diabetic children and adolescents. Insulin-induced lipodystrophies and allergic contact dermatitis caused by insulin pumps or glycaemic sensors are the most common skin reactions in these patients. Furthermore, several diabetes-associated skin diseases such as necrobiosis lipoidica, granuloma annulare, vitiligo, and bullosis diabeticorum may already be present in paediatric patients. Paediatric diabetes specialists should pay attention to their patients' skin to recognize these disorders, identify the potential causes, and choose the most suitable treatment. Finally, the evaluation of skin concentrations of advanced glycation end-products using non-invasive diagnostic techniques may be used to assess the risk of chronic complications of diabetes as early as adolescence.

Non-Infectious Granulomatous Dermatoses: A Pathologist's Perspective

Granulomatous dermatitis (GD) is one of the commonest tissue reaction patterns encountered in dermatopathology practice. Granulomatous inflammation in the skin can be seen in a wide range of conditions, thus, granulomatous dermatitis always poses significant challenge even to the astute dermatologists and dermatopathologists. Broadly, granulomatous dermatitis is divided into two groups-infectious and non-infectious, the prevalence of both highly variable and show overlapping pathology. However, there are subtle histological clues, which when combined with clinical features, help to narrow down the differential diagnosis. Thus, a good Clinicopathological correlation (CPC) along with histochemical stains, culture and ancillary techniques including molecular studies are required for arriving at a definite diagnosis. In this review, we shall discuss the histological clues to diagnose non-infectious granulomatous dermatitis (NIGD) and their differential diagnoses.

Histopathologic features of noninfectious granulomatous disorders involving the skin

Granulomatous dermatoses may represent primary skin inflammation or can serve as the harbinger of a multitude of underlying systemic disorders or drug reactions. Taken together with clinical findings, the microscopic features from skin biopsy can allow recognition of various patterns and facilitate a precise diagnosis. Accurate classification of entities in this category of inflammatory dermatoses may prompt clinicians to investigate for underlying systemic problems, thereby allowing the pathologist to add considerable value in the care of affected patients. This review article categorizes clinical and microscopic features of common and uncommon causes of noninfectious dermal and subcutaneous granulomatous inflammation.