Granuloma annulare: Clinical and histologic variants, epidemiology, and genetics

Therapeutic success of tofacitinib in granuloma annulare: A retrospective case series of 15 patients

Background Granuloma annulare (GA) is a necrobiotic granulomatous disorder that may sometimes be resistant to treatment, especially the generalised form. Tofacitinib has recently shown promise in the treatment of non-infective granulomatous dermatosis. Objectives In this study, we aimed to evaluate the response of generalised GA to oral tofacitinib. Methods This was a retrospective case series in patients of generalised GA who were treated with oral tofacitinib 5 mg twice a day in a tertiary care centre in north India. Baseline clinical details and histopathological findings were reviewed. Treatment response was noted in the form of clearance of lesions (complete or partial) along with the time taken to achieve the maximum response. Results A total of 15 patients of generalised GA were included in this study, amongst whom nine patients were resistant to conventional therapies whilst the remaining were treatment naïve. Complete clearance of lesions was noted in 11 patients at a mean treatment duration of 4.4 ± 2.1 months whereas clearance was partial in four, with a mean follow-up duration post- treatment in patients who had partial clearance, which is 7.3 ± 2.8 month, with a reduction in erythema and infiltration in those lesions. Adverse effects in the form of hyperlipidemia were observed in two patients. Conclusion Tofacitinib, a JAK-STAT inhibitor is beneficial in treating GA, especially in those with generalised and recalcitrant disease.

Granuloma Annulare Exhibits Mixed Immune and Macrophage Polarization Profiles with Spatial Transcriptomics

Granuloma annulare (GA) is an idiopathic condition characterized by granulomatous inflammation in the skin. Prior studies have suggested that GA develops from various triggers, leading to a complex interplay involving innate and adaptive immunity, tissue remodeling, and fibrosis. Macrophages are the major immune cells comprising GA granulomas; however, the molecular drivers and inflammatory signaling cascade behind macrophage activation are poorly understood. Histologically, GA exhibits both palisaded and interstitial patterns on histology; however, the molecular composition of GA at the spatial level remains unexplored. GA is a condition without Food and Drug Administration-approved therapies despite the significant impact of GA on QOL. Spatial transcriptomics is a valuable tool for profiling localized, genome-wide gene expression changes across tissues, with emerging applications in clinical medicine. To improve our understanding of the spatially localized gene expression patterns underlying GA, we profiled the spatial gene expression landscape from 6 patients with GA. Our findings revealed mixed T helper 1 and T helper 2 signals comprising the GA microenvironment and spatially distinct M1 and M2 macrophage polarization characteristics. IFN-γ and TNF signals emerged as important regulators of GA granulomatous inflammation, and IL-32 emerged as a key driver of granulomatous inflammation. Overall, our spatial transcriptomics data indicate that GA exhibits mixed immune and macrophage polarization.

Characterizing Granuloma Annulare in 73 Pediatric Patients

Background

Granuloma annulare (GA) is a common, benign, idiopathic inflammatory dermatosis. Aside from case reports and small studies, there are limited data about the characteristics of GA in children.

Objective

This study aimed to better characterize the epidemiologic and clinical features, triggering factors, disease associations, and outcomes of GA in the pediatric population.

Methods

We conducted a retrospective study of 73 pediatric patients diagnosed with GA at the University of Rochester Medical Center over a 7-year period.

Results

The most common subtype was localized GA (71.2%, n = 52), followed by subcutaneous (also known as "deep GA"; 16.4%, n = 12) and generalized (12.3%, n = 9) subtypes. Over 90% of patients had idiopathic GA, with the remaining patients reporting viral infection or trauma as triggers. Half of the patients studied had comorbid conditions, most frequently atopic dermatitis (17.8%, n = 13), obesity (9.59%, n = 7), asthma (6.85%, n = 5), and allergic rhinitis (6.85%, n = 5). The median duration of the disease was 11.00 months (interquartile range (IQR) 15.75 months); generalized GA had the shortest duration (median 10.00 months, IQR 15.50 months), while subcutaneous GA had the longest duration (median 12.00 months and IQR 29.00 months). Although recurrence rates for subcutaneous and generalized GA were high at 45.5% and 33.3%, respectively, most patients achieved clearance or improvement with treatment.

Conclusion

Most cases of GA in our study were idiopathic, with no clear differences between GA subtypes and associated comorbidities. Topical steroids were the most prescribed treatment with mixed efficacy.

Clinicopathologic evaluation of granuloma annulare: Study of 136 Iranian cases, south of Iran

Background and Objectives

Granuloma annulare (GA) is a benign skin disorder with various histopathologic features that are rarely investigated in Iranian population. We performed this study to find out the clinical and histopathologic features of GA in our referral centre.

Methods

One hundred-thirty-six patients with biopsy-proven GA were reviewed. Clinical data and pathological features were recorded.

Results

One hundred-eight female patients and 28 male patients (Female/male ratio: 3.85) with mean age of 42.54 ± 21.2 years (range: 2-83 years) were recruited. Eighty-eight (64.7%) patients had interstitial infiltrative pattern and 48 (35.3%) patients had complete palisading granulomas. The infiltrate occupied both upper and lower dermis in most of the cases (67.7%). Significant mucin was detected more commonly in complete GA compared to interstitial GA (p = 0.019), but inflammation degree, eosinophils, plasma cells, and giant cells were not different between two subtypes of GA (p > 0.05). The significant inflammation contained more significant plasma cells (p = 0.006). The significantly more giant cells were detected in patients between 20 and 60 years of age (p = 0.015); but other factors were not different between age groups.

Conclusions

In our study, the prevalence of GA in women was significantly higher than in men. Interstitial GA was the more common histological subtype and the inflammation was less severe and the infiltrate was mostly pandermal in our cases. More severe inflammation contained more plasma cells, and more dense giant cells were seen in middle aged patients.

Papular Umbilicated Granuloma Annulare in a Patient With Systemic Lupus Erythematosus

Granuloma annulare (GA) is characterized by palisading granuloma, which is histopathologically distinguished by histiocytes arrayed in a palisade configuration encircling insoluble entities associated with degenerated collagen fibrils. The present case demonstrated multiple cutaneous papules showing palisading granuloma in a patient with SLE. A 39-year-old woman has been taking oral prednisolone daily, hydroxychloroquine sulfate, and belimumab for systemic lupus erythematosus (SLE). A few papules appeared on the lateral side of the left arm and gradually increased around both sides. Physical examination found multiple firm skin-colored papules ranging in diameter from 2 to 3 mm on both forearms. Some of the papules had umbilicated tops. Histopathological examination showed degenerated collagen fibers with mucin deposition surrounded by histiocyte infiltrates in the dermis. These findings are characteristic of palisading granuloma. There are several GA variants, such as generalized, subcutaneous, and perforating GA. We considered several possibilities of the mechanisms underlying characteristic histological changes; atypical generalized GA variants, dermatofibroma, and granuloma associated with cutaneous vasculitis. We made the final diagnosis of papular umbilicated GA in the context of SLE.

Molecularly Targeted Therapies for Inflammatory Cutaneous Granulomatous Disorders: A Review of the Evidence and Implications for Understanding Disease Pathogenesis

Inflammatory cutaneous granulomatous diseases, including granuloma annulare, cutaneous sarcoidosis, and necrobiosis lipoidica, are distinct diseases unified by the hallmark of macrophage accumulation and activation in the skin. There are currently no Food and Drug Administration-approved therapies for these conditions except prednisone and repository corticotropin injection for pulmonary sarcoidosis. Treatment of these diseases has generally been guided by low-quality evidence and may involve broadly immunomodulatory medications. Development of new treatments has in part been limited by an incomplete understanding of disease pathogenesis. Recently, there has been substantial progress in better understanding the molecular pathogenesis of these disorders, opening the door for therapeutic innovation. Likewise, reported outcomes of treatment with immunologically targeted therapies may offer insights into disease pathogenesis. In this systematic review, we summarize progress in deciphering the pathomechanisms of these disorders and discuss this in the context of emerging evidence on the use of molecularly targeted therapies in treatment of these diseases.

Annular Erythemas and Purpuras

Annular dermatoses are a heterogeneous and extremely diverse group of skin diseases, which share in common annular, ring-like patterns with centrifugal spreading. Numerous skin diseases can sometimes display annular lesions, but some specific skin conditions are originally annular. We take the opportunity to review here mainly the causes of primary annular erythemas and their differential diagnoses, but also the rare causes of annular purpuras.

Granulomatous annular diseases

Granulomatous skin disorders comprise a large group of diseases that are typically characterized by granuloma formation both in the skin and in many other tissues. Cutaneous lesions are usually seen as erythematous papules and plaques that may occasionally be arranged in an annular, ringlike configuration. The etiopathogenesis is unclear in most cases, and granuloma formation may be associated with various systemic, infectious, and metabolic disorders, foreign bodies, environmental antigens, or malignancies. Treatment options are dependent on the etiology, extent, and severity of the lesions. This review includes the clinical, histopathologic, and dermatoscopy findings, differentials, and treatment options for noninfectious granulomatous annular skin disorders.

Skin disorders and interstitial lung disease: Part II-The spectrum of cutaneous diseases with lung disease association

Part 2 of this 2-part CME introduces dermatologists to noninfectious inflammatory skin diseases associated with pulmonary involvement. In many cases, dermatologists may be the first physicians recognizing respiratory complications associated with these diagnoses. Because pulmonary involvement is often the leading cause of morbidity and mortality, dermatologists should be comfortable screening and monitoring for lung disease in high-risk patients, recognizing cutaneous stigmata of lung disease in these patients and referring to pulmonary specialists, when appropriate, for prompt treatment initiation. Some treatments used for skin disease may not be appropriate in the context of lung disease and hence, choosing a holistic approach is important. Interstitial lung disease and pulmonary hypertension are the most common pulmonary complications and a significant cause of mortality in autoimmune connective tissue diseases, especially systemic sclerosis, dermatomyositis, and mixed connective tissue disease. Pulmonary complications, notably interstitial lung disease, are also common and life-threatening in sarcoidosis and vasculitis, while they are variable in neutrophilic and autoimmune blistering diseases.

Granuloma annulare after SARS-CoV-2 vaccination: A case report and a literature review

INTRODUCTION

During the Cov-19 pandemic, many studies reported a broad spectrum of cutaneous reactions presenting as erythematous rashes or pernio-like, urticaria-like or vesicular/bullous patterns associated with Cov-19-infection and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination.

METHODS

The authors documented the clinical and histopathological features of an unexpected case of granuloma annulare (GA) arising a few days after the SARS-CoV-2 vaccination and reviewed all GAs reported in the literature following the SARS-CoV-2 vaccination and Cov-19-infection.

CASE REPORT

A 69-year-old woman developed a single reddish lesion on the left deltoid region, where the SARS-CoV-2 vaccine seven days earlier was injected. The clinicians performed a punch skin biopsy, and histology revealed an interstitial GA.

CONCLUSIONS

Clinicians should be aware of the potential, though rare, GA occurrence as a possible adverse event after the SARS-CoV-2 vaccination. This additional case, like what happens after the administration of other vaccines, supports the idea that GA may result from the immune system activation following the vaccination. However, notwithstanding, they should encourage their patients to obtain immunization to assist the public health systems in overcoming the COVID-19 pandemic.

Intensively Pruritic Annular Papules on the Extremities of a Middle-aged Woman

A woman in her 50s presented with a 3-month history of intensively pruritic papules rapidly spreading on her extremities. What is your diagnosis?

The epifascial cap: A typical imaging sign for subcutaneous granuloma annulare in children

Objectives

Subcutaneous granuloma annulare (SGA) is a rare, self-limiting granulomatous disease in children, commonly diagnosed by histopathology following biopsy or surgical excision. This study aimed to identify imaging clues for SGA that could expedite accurate diagnosis and avoid the need for biopsy in children.

Methods

We retrospectively analyzed complete hospital records of all children diagnosed with SGA at our institution from January 2001 to December 2020. Detailed disease history, imaging findings, management, and outcome were evaluated.

Results

We identified 28 patients (20 girls) at a median age of 3.75 (range 1-12.5 years). Ten patients presented with multiple lesions. Most lesions were located on the lower extremities (n = 26/41). Ultrasound examinations were performed on all patients, and 12 (43%) patients also received an MRI. Surgical intervention was conducted in 18 (64%) patients either by incisional biopsy (n = 6) or total excision of the lump (n = 12). In all patients who did not undergo surgery, SGA resolved spontaneously. A careful review of the MRIs led to the discovery of a characteristic imaging shape of SGA lesions: the epifascial cap with a typical broad circular base laying on the fascia, extending towards the subdermal/dermal tissue. This distinctive shape was evident in every patient in our cohort.

Conclusions

The "Epifascial Cap Sign" is a specific imaging sign for SGA, which to the best of our knowledge, helps distinguish this disease from other subcutaneous lesions. Recognition of this novel diagnostic sign combined with the historical and physical findings should enable clinicians to establish SGA diagnosis easily and diminish the need for further invasive diagnostic procedures.

Immunohistochemical Features of MMP-9 and pSTAT1 in Granuloma Annulare and Sarcoidosis: A Comparative Study of 62 Cases

Background

Granuloma annulare (GA) and sarcoidosis are granulomatous inflammatory diseases that share similarities.

Objective

To identify the histological and immunohistochemical (IHC) features of GA and sarcoidosis.

Methods

A retrospective review of 36 patients with GA and 26 with sarcoidosis was performed. Results from hematoxylin and eosin (H&E) staining and IHC staining of MMP-9 and pSTAT1 within the skin lesions of GA and sarcoidosis were analyzed, and random forest was applied for developing a predictive model.

Results

Significantly greater expressions of MMP-9 (especially in elastic fibers, EFs, P < 0.0001) and pSTAT1 (P = 0.0003) were observed in lesion samples of GA versus sarcoidosis patients. In GA patients, MMP-9 was significantly upregulated in the interstitial type (P = 0.0222), while staining of pSTAT1 was positively correlated with the area of mucinous collagen in palisading GA (R = 0.5356, P = 0.0484). In sarcoidosis patients, MMP-9 (R = -0.7127, P = 0.0009) and pSTAT1 (R = -0.5604, P = 0.0067) were found to show stronger expressions in lesions with less lymphocyte infiltration. The predictive model demonstrated an AUC of 0.9675.

Conclusion

These results indicate that MMP-9 and pSTAT1 might exert roles in granulomatous inflammation in different modes, and the presence of more robust MMP-9 staining in EFs appears to be more suggestive of GA.

A case of knuckle pad syndrome in a middle-aged man

Knuckle pads are benign papules, nodules, or plaques overlying joints and typically manifest at the proximal interphalangeal joints (PIPs). They may be confused with other dermatologic or rheumatologic diseases. Treatment options for primary knuckle pads are limited and acquired knuckle pads typically improve with withdrawal of the offending insult.

The association of anxiety with granuloma annulare: a case-control study of the National Institutes of Health 'All of Us' research programme

Dear Editor, Granuloma annulare (GA) is an inflammatory skin disease that has been associated with diabetes, dyslipidaemia, hypothyroidism and autoimmune disorders.1,2 The annualized incidence and prevalence of GA in the USA are approximately 0.04% and 0.06%, respectively (with a female predominance).3 GA is clinically classified as localized (75% of cases), generalized or subcutaneous.4 There is a body of evidence supporting an association between several inflammatory dermatoses, such as psoriasis, and mental health conditions.5 Improvement of depression and anxiety following treatment of certain inflammatory dermatoses has also been described.5 It has been postulated that this association may, in part, relate to proinflammatory cytokines, which have been proposed to mechanistically connect inflammatory dermatoses and mental health conditions.6 A recent nested case-control study demonstrated a significant association of GA with depression, insomnia, opioid dependence and post-traumatic stress disorder.7 This study aims to investigate whether an association exists between GA and anxiety.

A Unique Case of Squamous Cell Carcinoma Presenting Within a Lesion of Granuloma Annulare

Granuloma annulare (GA) is a common benign granulomatous inflammatory disorder of the dermis or subcutis with classic morphologic and histologic presentation. Common clinical subtypes of granuloma annulare include localized, generalized, subcutaneous, perforating, and patch types. A biopsy is critical in cases of granuloma annulare with atypical features. We present a case of a 58-year-old male who presented with an annular scaly erythematous plaque on the right dorsal hand. Shave biopsy demonstrated irregular nests of mildly atypical squamous epithelium present within the superficial dermis, with abundant histiocytes and multinucleated giant cells arranged in palisades peripherally. These findings were consistent with invasive well-differentiated squamous cell carcinoma (SCC) with surrounding granuloma annulare. This case highlights a unique presentation in which clinicopathologic correlation is critical prior to arriving at a correct diagnosis.

Granuloma Annulare: An Updated Review of Epidemiology, Pathogenesis, and Treatment Options

Granuloma annulare (GA) is an inflammatory granulomatous skin disease that can be localized (localized GA) or disseminated (generalized GA), with patch, perforating, and subcutaneous subtypes being less common variants of this benign condition. Recently, new research has emerged that further elucidates GA epidemiology and etiopathogenesis; importantly, new therapeutic options for GA have also been described, although there remains a paucity of randomized controlled studies. In this review, we summarize recent updates on GA epidemiology and etiopathogenesis and offer an updated review of the therapeutic options for GA currently reported in the literature. We hope that the current review galvanizes randomized controlled studies that will in turn help lead to the recommendation of evidence-based treatments for GA.

Is biologic therapy the future of granuloma annulare treatment?

Granuloma annulare (GA) is a benign inflammatory skin disease that presents with erythematous papules and annular plaques. The pathogenesis of GA remains unknown and may potentially involve type 1 T helper cell (Th1)-mediated delayed-type hypersensitivity reaction. GA is associated with many conditions such as malignancy, trauma, thyroid disease, diabetes mellitus, and viral infection. The role of biological treatment is under investigation. In this article, we present a case of GA development following systemic treatment of psoriatic arthritis in a 59-year-old patient; golimumab therapy resulted in the successful treatment of both psoriatic arthritis and GA. This is the first case report describing GA therapy using golimumab.

Management of a Unique Presentation of a Common Dermatologic Condition

CONTEXT

Skin rashes are a common complaint seen in the primary care setting. There are many dermatologic conditions which a primary care provider (PCP) should be able to recognize and manage. One such condition is granuloma annulare (GA), which commonly presents as smooth, annular plaques on the trunk and/or extremities. Rashes like GA rarely present as unique variants and may be difficult for PCPs to determine from patient history and physical exam alone. Patch granuloma annulare (patch GA) is an example that may clinically mimic a cutaneous lymphoma known as mycosis fungoides (MF). PCPs should ideally be able to recognize the utility of performing a skin biopsy and/or referring the patient to a dermatologist when history and physical exam alone are insufficient. The histologic findings of skin biopsies often become essential in establishing a proper diagnosis and guiding patient management in unique dermatologic variants.

EXAMPLE CASE

The patient in this clinical practice report is a Caucasian female in her late 60s who presented to a dermatology clinic with a two-year history of a worsening widespread eruption on her trunk and extremities. She had been evaluated previously by her PCP about 4 months prior and, without obtaining skin biopsies, treated her with a medium potency topical corticosteroid cream. The eruption had spread over her hips, buttocks, back, thighs, wrists, and elbows. Multiple skin biopsies of affected sites were taken by the second author and revealed findings consistent with patch GA. The patient was started on topical betamethasone dipropionate 0.05% ointment twice daily and noted marked improvement of her symptoms.

CONCLUSIONS

Although GA is a benign condition of the skin that may be readily detected by PCPs, skin biopsies may be necessary to establish a proper diagnosis when this condition presents as a unique variant (e.g., patch GA). Therapy for patch GA often begins with a trial of high-potency topical steroid therapy in combination with ultraviolet light exposure, depending on disease severity and patient preference. Early evaluation with a skin biopsy by her PCP or an earlier referral to a dermatologist to have skin biopsies performed likely would have helped establish a prompter diagnosis and treatment plan for this patient.

Multiple roles of macrophage in skin

More than 100 years have passed since Elie Metchnikoff discovered macrophage. Over the recent decade, attracting information about macrophage polarization have been reported. This is because many molecules have been identified as markers of macrophage polarization. Additionally, mechanistic insights have been demonstrated by experiments with various stimuli-induced macrophage polarization. Historically and simply, macrophages are divided into M1 (classically activated) and M2 (alternatively activated). However, some of them are not specific yet. Studies in the field of cardiology revealed the plasticity of macrophages and their subsets are divided into details: Mhem, MHb, Mox and M4 macrophages. M2 macrophages were further divided in M2a, M2b, M2c and M2d. There appears to be more phenotypes of macrophages. However, there still lack studies in dermatological field. This review summarizes the spectrum of macrophage activation and finding about various roles of macrophages in the dermatological field.

Eosinophilic annular erythema

Eosinophilic annular erythema (EAE) is a rare eosinophilic dermatosis characterized by annular, erythematous papules and plaques commonly found on the trunk and the extremities. There is continued debate on whether EAE is a distinct entity or a clinical polymorphism of Well's syndrome, but it is generally considered a separate entity based on clinical and histopathological differences. We present a case of EAE and discuss the histopathological findings.

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.

Improvement of granulomatous skin conditions with tofacitinib in three patients: A case report

Granulomatous skin conditions are poorly understood inflammatory skin diseases consisting predominantly of macrophages. Granuloma annulare (GA) is the most common granulomatous skin disease and the generalized variant is particularly difficult to treat due to the prolonged course and lack of efficacious treatment options. Necrobiosis lipoidica (NL) is another granulomatous disorder of uncertain etiology. There is a growing body of evidence for the use of Janus kinase (JAK) inhibitors in the management of inflammatory skin diseases. In our report, we describe three patients with recalcitrant granulomatous disease including NL and generalized GA who responded favourably to treatment with the JAK inhibitor tofacitinib. JAK inhibitors may be a beneficial therapeutic option for patients with granulomatous skin diseases that are unresponsive to conventional therapies. Further research is required to determine the long-term efficacy and safety of JAK inhibitors in treating granulomatous skin conditions.

Incidence and Prevalence of Granuloma Annulare in the United States

Importance

Although several single-center studies have estimated that granuloma annulare may account for approximately 0.1% to 0.4% of new patients presenting to dermatologists, large-scale population-based studies estimating the prevalence and incidence of granuloma annulare are lacking.

Objectives

To estimate the population-based incidence and prevalence of granuloma annulare in the United States and to identify the most commonly prescribed treatments.

Design, Setting, and Participants

This cross-sectional study used deidentified data from the Optum Clinformatics Data Mart Database from January 1, 2017, to December 31, 2018, to identify patients with granuloma annulare.

Main Outcomes and Measures

After validating an approach to classify patients with granuloma annulare using International Statistical Classification of Diseases and Related Health Problems, Tenth Revision codes, the primary outcomes were age-, sex-, and race/ethnicity-specific annualized incidence and prevalence estimates for granuloma annulare. In addition, treatment use within 6 to 12 months after the first diagnosis of granuloma annulare was examined. Confidence intervals for prevalence and incidence estimates were computed assuming a binomial distribution using the Wilson score method. Age-, sex-, and race/ethnicity-specific incidence and prevalence estimates were compared using the χ2 test.

Results

A total of 11 608 patients with incident granuloma annulare (8680 female patients [74.8%]; mean [SD] age, 56.5 [18.8] years) and 17 862 patients with prevalent granuloma annulare (13 548 female patients [75.8%]; mean [SD] age, 56.6 [18.5] years) were identified during the study period. The overall annualized incidence of granuloma annulare was 0.04%, or 37.9 (95% CI, 36.9-38.9) per 100 000, and the overall annualized prevalence of granuloma annulare was 0.06%, or 58.3 (95% CI, 57.1-59.5) per 100 000. The incidence and prevalence of granuloma annulare were highest in the fifth decade of life. The incidence and prevalence of granuloma annulare were higher among women (incidence: female to male ratio, 2.8:1; prevalence: female to male ratio, 3.0:1). Within 6 months of their first diagnosis, 4822 patients (41.5%) filled a prescription for a topical corticosteroid, and 1087 patients (9.4%) received an intralesional injection. Within 6 months of their first diagnosis, oral tetracycline prescriptions were filled by 820 patients (7.1%), and hydroxychloroquine prescriptions were filled by 268 patients (2.3%).

Conclusions and Relevance

Granuloma annulare is a rare disease in the United States that is more common among women and middle-aged to older individuals. The findings of this cross-sectional study provide important background regarding the basic epidemiology and overall burden of granuloma annulare in the United States. Future studies are needed to better understand the association of granuloma annulare with quality of life and the most optimal treatment approaches for this condition.

Association of Granuloma Annulare With Type 2 Diabetes, Hyperlipidemia, Autoimmune Disorders, and Hematologic Malignant Neoplasms

IMPORTANCE

Although granuloma annulare (GA) has been associated with several other conditions, these studies have been limited by single-center designs and small sample sizes.

OBJECTIVE

To evaluate whether there is an association between GA and type 2 diabetes, hyperlipidemia, autoimmune conditions, and hematologic malignant neoplasms, using a large population-based cohort study.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study conducted between January 1, 2016, and June 30, 2019, used deidentified data from the US Optum Clinformatics Data Mart Database. A total of 5137 patients with GA were matched by age and sex with up to 10 randomly selected controls (n = 51 169) with a diagnosis of a nevus or seborrheic keratosis.

MAIN OUTCOMES AND MEASURES

Logistic regression was used to evaluate for potential associations between GA and diabetes, hyperlipidemia, autoimmune conditions, and hematologic malignant neoplasms. All analyses were adjusted for race/ethnicity, income, and educational level.

RESULTS

This study included 5137 individuals with GA (3760 women [73.2%]; mean [SD] age, 57.7 [19.0] years) and 51 169 controls (37 456 women [73.2%]; mean [SD] age, 57.7 [19.0] years). Those with GA were more likely than controls to have baseline diabetes (1086 [21.1%] vs 6780 [13.3%]; adjusted odds ratio [aOR], 1.67; 95% CI, 1.55-1.80), hyperlipidemia (1669 [32.5%] vs 14 553 [28.4%]; aOR, 1.15; 95% CI, 1.08-1.23), hypothyroidism (727 [14.2%] vs 5780 [11.3%]; aOR, 1.24; 95% CI, 1.15-1.36), and rheumatoid arthritis (62 [1.2%] vs 441 [0.9%]; aOR, 1.34; 95% CI, 1.02-1.75). Those with GA were more likely to have incident diabetes (144 [2.8%] vs 1061 [2.1%]; aOR, 1.31; 95% CI, 1.10-1.57), hypothyroidism (41 [0.8%] vs 252 [0.5%]; aOR, 1.59; 95% CI, 1.14-2.22), systemic lupus erythematosus (21 [0.4%] vs 65 [0.1%]; aOR, 3.06; 95% CI, 1.86-5.01), and rheumatoid arthritis (26 [0.5%] vs 122 [0.2%]; aOR, 2.05; 95% CI, 1.34-3.13). There was no association between GA and an increased risk of hematologic malignant neoplasms.

CONCLUSIONS AND RELEVANCE

This population-based cohort study identified associations between GA and baseline diabetes and hyperlipidemia as well as between GA and both baseline and incident autoimmune conditions. These findings suggest that diabetes and hyperlipidemia may be risk factors for the development of GA and that autoimmunity may be an important factor in the pathogenesis of GA.

Granulomas in Dermatopathology: Principal Diagnoses - Part 2

Part 2 of this series on granulomatous diseases focuses on skin biopsy findings. Whereas the first part treated noninfectious conditions (metabolic disorders and tumors, among other conditions), this part mainly deals with various types of infectious disease along with other conditions seen fairly often by clinical dermatologists.

A Review of the Dermatological Complications of Giant Cell Arteritis

Giant cell arteritis (GCA) is characterized by granulomatous inflammation of large and medium-sized vessels. It is the most common vasculitis among elderly people in Europe and North America. GCA usually presents with ischemic cranial manifestations such as headache, scalp tenderness, visual manifestations, and claudication of the tongue and jaw. Thickness and tenderness of temporal arteries are the most recognizable signs of GCA on physical examination. Laboratory tests usually show raised acute phase reactants. Skin manifestations are uncommon in GCA and are rarely found as a presenting symptom of GCA. Necrosis of the scalp and tongue is the most common ischemic cutaneous manifestation of GCA. Although infrequent, when present it reflects severe affection and poor prognosis of GCA. Panniculitis-like lesions have been reported in the setting of GCA, with nodules being the most common finding. Other entities, such as generalized granuloma annulare or basal cell carcinoma have been occasionally described in GCA patients. Prompt recognition and initiation of therapy are crucial to prevent serious complications of GCA. When high suspicion of GCA exists, immediate administration of glucocorticoids is recommended. It is advisable to refer the patient to a specialist GCA team for further multidisciplinary assessment.

Localized Versus Generalized Granuloma Annulare: A Retrospective Review of 407 Patients

BACKGROUND

Granuloma annulare has been linked to diabetes, dyslipidemia, thyroid disease, collagen vascular disease, malignancies, infectious hepatitis, and systemic infections. However, these associations have not been systematically investigated when categorized by its clinical variants.

OBJECTIVE

To evaluate disease associations of localized and generalized granuloma annulare.

METHODS

In total, 407 granuloma annulare patients from 1989 to 2019 were retrospectively reviewed, categorized by clinical variant (localized or generalized), age (pediatric or adult), and diagnostic method (clinical or histologic). Descriptive statistical analyses and multivariate logistic regression analysis were performed. Fisher's exact tests were conducted to produce unbiased probability values.

RESULTS

Overall, 75.2% of the study sample was female, 47.2% had dyslipidemia, 24.8% were diabetic, and 24.6% had thyroid disease. Dyslipidemia (OR 2.15, CI 1.95-2.35, P < .001), diabetes (OR 1.16, CI 1.01-1.31, P = .041), and histologic diagnosis (OR 2.08, CI 1.21-3.52, P = .007) were associated with increased risk of GGA compared to LGA. When stratified by adult versus pediatric cases, dyslipidemia and diagnostic method remained significant, but diabetes did not.

CONCLUSIONS

Evaluating granuloma annulare by its clinical variants may help to determine disease associations with each variant.

Granuloma annulare subtypes: sonographic features and clinicopathological correlation

PURPOSE

Diagnosis of granuloma annulare (GA) is based on the clinical and histopathological findings. However, only sporadic case reports of subcutaneous GA sonography have been published to date. The objective of this study was to evaluate the ultrasonographic patterns of the different clinical variants of GA: localized, generalized, subcutaneous, and perforating.

METHODS

In this retrospective observational study, we analyzed and correlated the clinical, histopathological, and sonographic features of 15 patients diagnosed with GA.

RESULTS

We included 8 women and 7 men with a mean age of 48.4 years (8-77 years). We found three different sonographic patterns depending on the clinical variant of GA: poorly defined hypoechoic band including the dermis (dermal pattern), irregularly shaped hypoechoic hypodermal lumps (hypodermal pattern), and ill-defined hypoechoic dermal and subcutaneous lesions (mixed pattern). Five cases showed increased blood flow signal on Doppler interrogation.

CONCLUSION

Although our findings are broadly consistent with the previous reports of subcutaneous GA, the sonographic features in localized, generalized, and perforating GA have not been previously reported.

Treatment of granuloma annulare and suppression of proinflammatory cytokine activity with tofacitinib

BACKGROUND

Granuloma annulare (GA) is a common cutaneous inflammatory disorder characterized by macrophage accumulation and activation in skin. Its pathogenesis is poorly understood, and there are no effective treatments. The potential health implications of severe GA are unknown.

OBJECTIVE

We sought to better understand GA pathogenesis and evaluate a molecularly targeted treatment approach for this disease.

METHODS

We used single-cell RNA sequencing to study the immunopathogenesis of GA and also evaluated the efficacy of tofacitinib (a Janus kinase 1/3 inhibitor) in 5 patients with severe, long-standing GA in an open-label clinical trial.

RESULTS

Using single-cell RNA sequencing, we found that in GA lesions IFN-γ production by CD4⁺ T cells is upregulated and is associated with inflammatory polarization of macrophages and fibroblasts. In particular, macrophages upregulate oncostatin M, an IL-6 family cytokine, which appears to act on fibroblasts to alter extracellular matrix production, a hallmark of GA. IL-15 and IL-21 production appears to feed back on CD4⁺ T cells to sustain inflammation. Treatment of 5 patients with recalcitrant GA with tofacitinib inhibited IFN-γ and oncostatin M, as well as IL-15 and IL-21, activity and resulted in clinical and histologic disease remission in 3 patients and marked improvement in the other 2. Inhibition of these effects at the molecular level paralleled the clinical improvement. Evidence of systemic inflammation is also present in some patients with severe GA and is mitigated by tofacitinib.

CONCLUSIONS

The Janus kinase-signal transducer and activator of transcription pathway is activated in GA, likely in part through the activity of IFN-γ and oncostatin M, and Janus kinase inhibitors appear to be an effective treatment.

Granulomatous Skin Diseases in a Tertiary Care Portuguese Hospital: A 10-Year Retrospective Study

Granulomatous skin diseases comprise an extensive group of pathologies whose diagnosis usually requires a histopathological examination. At this level, various types of granulomas can be distinguished, namely tuberculoid, sarcoid, necrobiotic, suppurative, xanthogranuloma, and foreign-body granulomas. This study aimed to determine the frequency and pattern of different granulomatous skin lesions in the Dermatopathology Department of Hospital de Santa Maria (Lisboa, Portugal). A retrospective study of all skin biopsies with granulomatous lesions received during a period of 10 years (2008-2017) was performed. Clinical and histopathological characteristics of the selected cases were analyzed, and the lesions were categorized according to histological type of granuloma and etiology. Foreign-body granulomas secondary to ruptured cyst, folliculitis, or suture material were excluded. From a total of 48,253 cutaneous biopsies performed in this period, 461 (1%) granulomatous lesions were included in our study. In the analysis according to type of granuloma, necrobiotic granulomas were the most frequent (N = 111; 27.0%), followed by sarcoidal (N = 72; 17.5%), tuberculoid (N = 51; 12.4%), suppurative (N = 45; 10.9%), foreign body (N = 40; 9.7%), and xanthogranulomas (N = 26; 6.3%). The remaining 20% corresponded to granulomas of other types. During these 10 years, the most frequent etiology was granuloma annulare (N = 98; 88.3%), followed by sarcoidosis (N = 47; 65.3%). Histopathology is a fundamental tool in the diagnosis of granulomatous skin diseases, allowing for the categorization of various types of granulomas and often guiding further investigation of these patients. The geographical area has an influence on the types of granulomas observed, as evidenced by comparing this study with others previously published.

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.

Annular Elastolytic Giant Cell Granuloma

Annular elastolytic giant cell granuloma (AEGCG) is a rare, often self-limiting chronic inflammatory disorder mostly occurring in the sun-exposed areas such as the dorsum of hands, extensor surfaces of arms, face, anterior neck, and upper chest. The pathognomonic histological findings include the presence of numerous granulomas associated with loss of elastic fibers that appear to be ingested by multi-nucleated giant cells. Here, we present a case of a 56-year-old woman with multiple, anatomically variable erythematous lesions- annular and papular, mainly in the upper body. The clinical presentation and histopathologic findings support our diagnosis.

Second-Strand Synthesis-Based Massively Parallel scRNA-Seq Reveals Cellular States and Molecular Features of Human Inflammatory Skin Pathologies

High-throughput single-cell RNA-sequencing (scRNA-seq) methodologies enable characterization of complex biological samples by increasing the number of cells that can be profiled contemporaneously. Nevertheless, these approaches recover less information per cell than low-throughput strategies. To accurately report the expression of key phenotypic features of cells, scRNA-seq platforms are needed that are both high fidelity and high throughput. To address this need, we created Seq-Well S3 ("Second-Strand Synthesis"), a massively parallel scRNA-seq protocol that uses a randomly primed second-strand synthesis to recover complementary DNA (cDNA) molecules that were successfully reverse transcribed but to which a second oligonucleotide handle, necessary for subsequent whole transcriptome amplification, was not appended due to inefficient template switching. Seq-Well S3 increased the efficiency of transcript capture and gene detection compared with that of previous iterations by up to 10- and 5-fold, respectively. We used Seq-Well S3 to chart the transcriptional landscape of five human inflammatory skin diseases, thus providing a resource for the further study of human skin inflammation.