Subcutaneous granuloma annulare (SGA) is a rare clinicopathologic subtype of granuloma annulare characterized by the presence of subcutaneous nodules. There are no present reviews synthesizing the clinical features and treatment modalities in SGA. We conducted a systematic review following PRISMA guidelines [CRD42022344672] on all peer-reviewed English-language studies that reported one or more cases of SGA. A total of 97 studies, comprising 26 case series and 71 case reports with 324 patients, were included for analysis. Most cases were predominantly pediatric, with 78.9% of the cases identified being age 16 or lower and a median age of diagnosis of 6. There was no overall gender predisposition. Although over two-thirds of patients did not have any comorbidities, diabetes mellitus was the most common comorbidity present in 4% of cases. The most common feature of SGA was nodules, which were present in 99.6% of patients. Pain or tenderness was reported in 15.4%, and erythema of overlying skin in 11.0% of cases. Surgical excision was performed in 96/141 (68.1%) patients. Among the 27/141 (18.0%) patients who were conservatively managed, 87.0% spontaneously improved, including 60.0% who completely self-resolved. Topical and intralesional steroids were used in 3.40% and 1.85% of patients, respectively, resulting in complete or partial resolution in 54.6% and 100%. Among patients who were followed up, 83/324 (25.6%) patients experienced recurrence after a median duration of 26 weeks. SGA is predominantly a pediatric disease that frequently occurs on the limbs and the head. Juxta-articular lesions are more commonly observed in adults than in children. Surgical excision is common and effective in most patients. Spontaneous improvement occurs in most untreated cases, and intralesional steroids but not topical steroids may be beneficial for non-resolving cases and to reduce time to resolution.

Subcutaneous dirofilariosis is a well-known disease caused mainly by Dirofilaria repens and described in several mammalian species including humans, dogs, and cats. Additionally, early developing stages of the heartworm Dirofilaria immitis are rarely reported in subcutaneous localization from humans and dogs. To our knowledge, confirmed clinical evidence of this condition has not been described in the cats yet, even if the feline hosts can be affected either by the classic adult-related heartworm form or heartworm-associated respiratory disease (HARD) caused by immature stages. A 2 year old, spayed male cat was presented for three subcutaneous nodules on the head and trunk. The cat lived in Northern Italy and was regularly vaccinated and treated monthly with an antiparasitic spot on formulation containing selamectin. One of the three nodules was surgically excised and examined. Histology showed the presence of a nodular lesion in the subcutis characterized by a severe inflammatory infiltrate composed of macrophages, small lymphocytes, with fewer eosinophils, and mast cells, supported by a proliferation of mature fibroblasts (fibrosis). Inflammatory cells were multifocally surrounding sections of parasites identified as adult nematodes. Microscopic features were compatible with D. immitis, which has been molecularly confirmed (98.2% identity to D. immitis isolate OP107739). The cat tested negative for D. immitis antigenemia and the two remaining nodules disappeared spontaneously in a few months. In region where heartworm is prevalent, aberrant localization of D. immitis should be considered in the differential diagnoses of subcutaneous filarial worms in cats and dogs.

BACKGROUND: Kimura\'s disease is a rare chronic inflammatory disorder of unknown etiology that is seen in people of Asian descent. It is characterized by head and neck subcutaneous nodules along with lymphadenopathy, which is usually solitary but can be generalized. It is diagnosed histopathologically by the proliferation of blood vessels and germinal centers in lymphoid follicles, along with variable degrees of fibrosis and extensive eosinophil infiltration. Its localized form is treated with surgical excision, while generalized lesions and those that do not respond to surgical excision can be managed with steroids or radiotherapy.
METHODS: In this report, we present the first case of Kimura\'s disease in the Ethiopian literature in a 40-year-old Ethiopian man that presented with generalized pruritic subcutaneous nodules and lymphadenopathy, which were effectively managed with a tapering course of prednisolone, and a relapse that showed good sustained response with slow steroid taper.
CONCLUSIONS: We have demonstrated that, even though it is very rare in the African continent, Kimura\'s disease is to be considered as a differential diagnosis for patients that present with subcutaneous nodules and lymphadenopathy. We also have demonstrated that relapses can be effectively managed with reinitiation of the same dose of steroids but with a very slow taper.

BACKGROUND: Pilomatricoma is a common but easily misdiagnosed tumor in children.
OBJECTIVE: To differentiate pilomatricoma from other common subcutaneous nodules in children.
METHODS: Misdiagnosed subcutaneous nodules in four children were recorded.
RESULTS: A red mass on a 7-year-old boy\'s head which had been misdiagnosed pyogenic granuloma was proved to be pilomatricoma. A red mass on an 8-month-old boy\'s face which had been misdiagnosed infantile hemangioma also turned to be pilomotricoma. A red mass on a 21-month-old girl\'s breast, which had been misdiagnosed pilomatricoma, was proved to be infantile myofibroma. A subcutaneous nodule under a 13-month-old girl\'s armpit, which had been misdiagnosed pilomatricoma, turned to be BCG-associated lymphadenitis.
CONCLUSIONS: When a child with a subcutaneous nodule attends, pilomatricoma, vascular tumors, fibrous tumors, and BCG-associated lymphadenitis should be considered.

UNASSIGNED: Cutaneous polyarteritis nodosa (CPAN) is a distinct clinical entity represented by a chronic, relapsing, benign course, with rare systemic involvement. Treatment is with CSs, CYC or other conventional synthetic DMARDs (csDMARDs). In this case series, we aimed to share our varied clinical experience of successfully treating patients with CPAN, with tofacitinib in a refractory/relapsing course or as upfront monotherapy without CSs/csDMARDs.
UNASSIGNED: We report this retrospective case series managed at our rheumatology centre in Bangalore from 2019 to 2022. Four patients identified as CPAN on biopsy were able to achieve disease-free remission with tofacitinib as part of their treatment, with no relapse on further follow-up. Our patients presented with subcutaneous nodules and cutaneous ulcers. After systemic evaluation, all the patients underwent skin biopsy, which showed fibrinoid necrosis in the vessel walls of the dermis, with a histopathological impression of CPAN. They were initially treated with a conventional approach of CSs with/without csDMARDs. On experiencing a refractory/relapsing course, tofacitinib was tried in all the patients as either CS sparing or upfront monotherapy without concomitant csDMARDs.
UNASSIGNED: Use of tofacitinib resulted in improvement of ulcers and paraesthesia and in gradual healing of skin lesions, albeit with scarring, with no further recurrence or relapse over a follow-up period of 6 months for all the patients. The therapeutic effect of tofacitinib was consistent when used either as CS sparing or as upfront monotherapy, thereby proving the drug to be a promising option that warrants larger trials in future to treat the subset of patients with established CPAN.
UNASSIGNED: Tofacitinib could be used for disease-free remission as monotherapy for CPAN either upfront or as CS sparing, even without concomitant csDMARDs, in those patients who are dependent on CSs or multiple DMARDs.

Sarcoidosis is an enigma diagnosed by ruling out other etiologies of granulomatous inflammation. The multisystem manifestations of sarcoidosis and the clinical polymorphism pose a diagnostic challenge to all physicians. The skin is the most commonly affected organ after the lungs in sarcoidosis. Dermatological manifestations can appear before, during, or after systemic involvement, and the type of skin lesion can have prognostic significance. Also, a biopsy of skin lesions is less invasive and more accessible to perform than a biopsy of visceral organs. Thus, in certain ways, cutaneous manifestations can aid in the diagnosis and prognosis of systemic disease. This article has focused on the frequently encountered skin lesions of sarcoidosis along with their prevalence, clinical features, and management.

To help clarify the clinical manifestations, diagnosis, and treatment for Whipple disease, we report a case of a man in China infected with Tropheryma whipplei. The patient had multiple subcutaneous nodules as the only manifestation, which was not consistent with the typical symptoms of T. whipplei infection.

Dirofilaria spp. nematodes are accidental parasites of humans causing mild to serious, superficial or visceral infections. Superficial dirofilariosis is rather common in Europe and is typically manifested as subcutaneous form. Herein we report 46 new cases of human dirofilariosis (19 patients with subcutaneous, 18 patients with ocular, 4 patients wih genital, 2 patients with submucosal, 2 patients with pulmonary and 1 patient with intramuscular form of infection) that were recorded from the beginning of 2015 to May 2021 on the Balkan Peninsula with a goal to update the prevalence of this parasitosis and point out potential problems in diagnosis and treatment. Besides, given the high possibility of misinterpretation as tumor, our second aim was to encourage the inclusion of this pathogen in the differential diagnosis of subcutaneous nodules. Although quite common forms, subcutaneous and ocular dirofilariosis can be very often misdiagnosed in clinical practice due to the absence of specific clinical manifestations. Therefore, raising awareness of clinicians about this zoonosis is needed as well as closer collaboration between physicians and veterinarians.

Rheumatoid arthritis (RA) was significantly associated with increased overall risk of periodontitis, both chronic, inflammatory pathologies leading to connective tissue breakdown and bone destruction. To identify clinical and/or serological variables routinely evaluated during follow-up of people with RA which are associated with the severity of their periodontal disease. An observational, cross-sectional study was carried out, which included RA patients according to ACR/EULAR 2010 criteria having chronic periodontal disease. RA clinical parameters (disease duration, erythrocyte sedimentation rate, serum C-reactive protein, disease activity (DAS28) and rheumatoid factor, presence of bone erosions and rheumatic nodules) and also corticosteroid therapy were considered. Periodontitis was evaluated according to the American Academy of Periodontology (1999) and chronic periodontitis was assessed by full mouth periapical radiographic examination, periodontal probing depth, clinical attachment level and bleeding index. A total of 110 subjects with RA and chronic periodontitis were included. The female/male relation was 5.1, and no significant differences between genres were found in rheumatic or oral variables. RA patients with longer disease duration, higher disease activity and with rheumatic nodules had significantly greater periodontitis severity. Multivariate analysis confirmed that severe periodontitis was associated with DAS283 4.1 (OR 51.4, CI 95% 9.4-281.5) and the presence of rheumatic nodules (OR 6.4, CI 95% 1.3-31.6). Disease activity and rheumatic nodules were strongly associated with severe periodontitis. Based on these findings it would be desirable to include interdisciplinary management at an early stage of RA to ensure comprehensive treatment of both pathologies.

Subcutaneous nodules are a rare adverse event following immunization frequently associated with suboptimal injection procedures and aluminium-containing vaccines. We present three cases of subcutaneous nodules following immunization describing their clinical signs, histopathological features and ultrasound findings and demonstrating the use of sonography as an aid to the diagnosis of this entity.