Neutrophilic dermatosis after azathioprine exposure

Azathioprine hypersensitivity: A Sweet-like syndrome

INTRODUCTION

Azathioprine hypersensitivity can occasionally present as Sweet-like syndrome, a dose-independent side effect characterized by the unanticipated onset of macules, papules, and pustules.

CASE PRESENTATION

A 35-year-old woman with systemic lupus erythematosus presented with complaints of generalized maculopapular rash, facial swelling, and bilateral lower extremity edema with a duration of 4 days and a 2-day history of constitutional symptoms within 2 weeks of the beginning of azathioprine therapy to treat existing lupus nephritis (class 2/3).

DISCUSSION

Patients who experience azathioprine hypersensitivity syndrome can present with erythema nodosum, small-vessel vasculitis, acute generalized exanthematous pustulosis, Sweet syndrome, and nonspecific dermatosis. The following signs and symptoms are used as criteria to diagnose drug-induced Sweet syndrome: (a) abrupt onset of painful erythematous plaques, (b) histopathological evidence of dense neutrophilic infiltrate without evidence of leukocytoclastic vasculitis, (c) temperature higher than 39.7°C, (d) temporal relationship between drug ingestion and clinical presentation, and (e) temporal resolution of lesions after drug withdrawal. Our patient met three out of five criteria and was diagnosed with Sweet-like syndrome.

CONCLUSION

Our case highlights the uncommonly presented azathioprine-induced Sweet-like syndrome that occurs abruptly after the commencement of the offending drug. This diagnosis can be established through basic laboratory workup and skin biopsy findings.

Clinical characteristics, diagnosis and management of Sweet syndrome induced by azathioprine

Sweet syndrome is a rare complication of azathioprine treatment with unelucidated clinical features. The purpose of this study was to investigate the clinical characteristics of azathioprine-induced Sweet syndrome (AISS) and provide a reference for diagnosis, treatment and prognosis. We collected relevant case reports of AISS by searching Chinese and English databases from 1960 to December 31, 2022, extracted the data and carried out a retrospective analysis. The median age of the 44 patients was 50 (range 9-89) years, and they included 32 males (72.7%). Fever (86.4%) and arthralgia (31.8%) were the most common clinical symptoms. The skin lesions were mainly pustules (54.5%), papules (40.9%), plaques (40.9%) and nodules (31.8%), which were mainly distributed on the extremities (54.5%), face (38.6%) and hands (36.4%). Laboratory examination revealed neutropenia (65.9%) as well as elevated C-reactive protein (63.6%) and erythrocyte sedimentation (40.9%) rates. Histopathology of the lesioned skin showed neutrophil infiltration (93.2%) and dermal edema (38.6%). Symptom relief was achieved at a median time of 7 days (range 2-28 days) after azathioprine discontinuation in all patients. Nine patients (20.5%) had skin lesions that recurred within 24 h after taking azathioprine again. Clinicians and pharmacists should grasp the regularity and characteristics of AISS and should not recommend the readministration of azathioprine, to avoid the recurrence of Sweet syndrome.

Azathioprine hypersensitivity syndrome manifesting as subcutaneous Sweet syndrome and acute pancreatitis

Azathioprine (AZA) is a commonly used immunosuppressive therapy that has been implicated in a number of cutaneous and systemic inflammatory reactions. Initiation of AZA has been associated with a hypersensitivity syndrome manifesting as acute pancreatitis and Sweet syndrome. Subcutaneous Sweet syndrome is a rare variant of Sweet syndrome where the dominant localization of inflammation is within the subcutaneous fat; it is commonly associated with underlying myeloproliferative disease. However, it has not been reported in the literature as a cutaneous manifestation of AZA hypersensitivity syndrome. We present a unique case of acute pancreatitis and biopsy-proven subcutaneous Sweet syndrome following the initiation of AZA with resolution upon discontinuation.

Azathioprine-induced hypersensitivity reaction mimicking sepsis in a patient with systemic lupus erythematosus

A 21-year-old woman with a history of systemic lupus erythematosus presented to the emergency department with acute-onset nausea, vomiting, and fevers. Two weeks prior, she was started on azathioprine 50 mg daily by her outpatient rheumatologist; the dose was up-titrated to 100 mg when repeat blood work showed no drug toxicity. The morning after increasing her dose, she was awoken by recurrent emesis. At presentation, she was febrile, tachycardic, and hypotensive. Her exam showed mild, generalised abdominal tenderness but was otherwise unremarkable. Lab work demonstrated elevated inflammatory markers, elevated liver transaminases, and stable hypocomplementemia. Chest X-ray and computed tomography abdomen/pelvis were unrevealing. She was given intravenous fluids and broad-spectrum antibiotics, and azathioprine was held. A thorough infectious workup returned negative. A flare of her systemic lupus erythematosus was considered but deemed an unlikely explanation of her systemic inflammatory response syndrome. With azathioprine discontinuation, she made a rapid, near-complete recovery within 24 h of admission, suggesting a diagnosis of azathioprine hypersensitivity syndrome. This case exemplifies the difficulty in distinguishing azathioprine hypersensitivity from mimickers such as infection and underlying autoimmune disease flare. Prompt recognition of hypersensitivity can lead to appropriate discontinuation of the drug and prevent future morbidity.

Systematic Review: Sweet Syndrome Associated with Inflammatory Bowel Disease

BACKGROUND AND AIMS

Sweet syndrome [SS] is a dermatological condition associated with both inflammatory bowel disease [IBD] and azathioprine use. We performed a systematic review to better delineate clinical characteristics and outcomes of SS in IBD patients.

METHODS

Peer-reviewed, full-text journal publications from inception to April 2020 in English language and adult subjects with IBD were included. Skin biopsy was required as SS gold-standard diagnosis. Azathioprine-associated SS required recent azathioprine introduction or recurrence of SS after azathioprine re-challenge.

RESULTS

We included 89 publications with 95 patients [mean age of SS diagnosis: 44 years; 59% female; 20 with azathioprine-associated SS and 75 without]. SS was diagnosed prior to IBD in 5.3%, at time of IBD diagnosis in 29.5% and after diagnosis in 64.2%. In total, 91% of patients with SS had known colonic involvement and the majority [76%] had active IBD at diagnosis; 22% had additional extra-intestinal manifestations. Successful therapies for SS included corticosteroids [90.5%], anti-tumour necrosis factor [TNF]-α inhibitor therapy [14.8%] and azathioprine [11.6%]. Azathioprine-associated SS was distinct, with 85% male patients, mean age of SS diagnosis of 50 years and a lower likelihood to be prescribed corticosteroids for treatment [75% vs 94.7% of non-azathioprine-associated SS, p = 0.008]. All patients with azathioprine-associated SS improved with medication cessation and developed recurrence after re-challenge.

CONCLUSIONS

SS may precede or occur with IBD diagnosis in almost one-third of cases. Azathioprine and IBD-associated SS present and behave distinctly, especially with regard to gender, age at diagnosis and recurrence risk. Corticosteroids and TNF-α inhibitors have demonstrated efficacy in treating SS in IBD.

Azathioprine hypersensitivity syndrome: report of two cases with cutaneous manifestations

Azathioprine is an immunosuppressant drug used in many dermatological and nondermatological pathologies. Azathioprine hypersensitivity syndrome (AHS) is a rare idiosyncratic reaction that is not related to dose or thiopurine methyltransferase activity. Up to half of cases of AHS can present with variable cutaneous manifestations besides fever, malaise and other systemic symptoms. It is important to be aware of AHS, as continuance or reintroduction of the drug can led to multiorgan failure and cardiovascular collapse.

Azathioprine Hypersensitivity Syndrome during Treatment of Severe Interstitial Lung Disease with Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis

Azathioprine is used to treat anti-neutrophil cytoplasmic antibody- (ANCA-) associated vasculitis. Azathioprine hypersensitivity syndrome is often missed. An 81-year-old man undergoing treatment for interstitial pneumonia developed a high fever and was diagnosed with ANCA-associated vasculitis based on an elevated myeloperoxidase- (MPO-) ANCA titer and renal biopsy findings. After induction therapy, his clinical symptoms improved, but his MPO-ANCA remained elevated (>300 U·L⁻¹) and hematuria persisted. Prednisolone plus azathioprine was administered as maintenance therapy. Three exacerbations of the inflammatory response occurred during the subsequent 3 months. In each instance, we suspected opportunistic infection or a flare-up of vasculitis. The first exacerbation was treated with an increased prednisolone dose and antibiotics. At the onset of the second exacerbation, which was accompanied by systemic erythema, we stopped azathioprine and administered antibiotics. The third exacerbation, which occurred the day after restarting azathioprine, involved a fever with chills and an acute inflammatory reaction; we therefore suspected an azathioprine allergy. A drug provocation test was performed, and a hyperinflammatory response was observed. The patient received prednisolone (15 mg·day⁻¹) monotherapy; no further fever was observed during the subsequent 2 months. We therefore diagnosed azathioprine hypersensitivity syndrome. Under treatment with prednisolone (5 mg·day⁻¹) and mycophenolate mofetil (1 g·day⁻¹) (replacing the azathioprine), no signs of relapse or infection have occurred for more than two years. Renal function and the pulmonary lesions are stable, although the high MPO-ANCA titer and hematuria persist. The diagnosis of azathioprine hypersensitivity is often delayed because of the difficulty in identifying the relationship between immunosuppressive agents and hypersensitivity and in distinguishing this from infection or relapse of the primary disease. The misdiagnosis of azathioprine hypersensitivity leads to unnecessary treatment; thus, clinicians should consider allergic reactions specific to azathioprine when switching from induction to maintenance therapy.

Neutrophilic drug reactions

Neutrophilic drug reactions are unique eruptions that can affect hospitalized patients and share a common pathophysiology with neutrophils as the key mediators of inflammation. They range in clinical presentation from papules and plaques to bullae and erosions to pustules. Although there is some overlap in presentation, each has distinguishing features that aid the clinician in differentiation from one another and from other drug hypersensitivity reactions. Much of the data on these reactions are from case reports and series or retrospective review studies. There are limited prospective observational studies dedicated to these adverse drug reactions. We review the more common and life-threatening neutrophilic drug reactions, their proposed mechanism of action, and their management.

Insights Into the Pathogenesis of Sweet's Syndrome

Sweet's syndrome, also known as Acute Febrile Neutrophilic Dermatosis, is a rare inflammatory condition. It is considered to be the prototype disease of neutrophilic dermatoses, and presents with acute onset dermal neutrophilic lesions, leukocytosis, and pyrexia. Several variants have been described both clinically and histopathologically. Classifications include classic Sweet's syndrome, malignancy associated, and drug induced. The cellular and molecular mechanisms involved in Sweet's syndrome have been difficult to elucidate due to the large variety of conditions leading to a common clinical presentation. The exact pathogenesis of Sweet's syndrome is unclear; however, new discoveries have shed light on the role of inflammatory signaling, disease induction, and relationship with malignancy. These findings include an improved understanding of inflammasome activation, malignant transformation into dermal infiltrating neutrophils, and genetic contributions. Continued investigations into effective treatments and targeted therapy will benefit patients and improve our molecular understanding of inflammatory diseases, including Sweet's syndrome.

Sweet syndrome: a rare feature of ANCA-associated vasculitis or unusual consequence of azathioprine-induced treatment

Background

Sweet syndrome is a rare skin condition characterised by fever, neutrophilia, and tender erythematous skin lesions and has been reported to occur in association with anti-neutrophil cytoplasmic antibodies (ANCA) as well as complicate treatment with azathioprine therapy. Azathioprine, a relatively safe immunosuppressive, is frequently used to maintain disease remission in the treatment of ANCA-associated vasculitis. The occurrence of Sweet syndrome in a patient with ANCA-positive vasculitis and following treatment with azathioprine prompted us to present this clinical case and share this unusually rare occurrence. In doing so, we also wish to discuss current understanding of the disease and plausible associations.

Case presentation

Herein, we discuss the case of a 54-year old white male, who presented with features of ANCA vasculitis with haemoptysis, arthralgia, abnormal kidney function with active urine sediment and a positive p-ANCA titre. Standard immunosuppressive treatment with corticosteroids and intravenous rituximab resulted in disease remission. Due to significant steroid side effects, his steroid treatment was gradually tapered and switched to azathioprine over a 6-month period. Two weeks following initiation of azathioprine, he developed a painful maculo-papular erythematous skin rash and fever. A skin biopsy confirmed classical features consistent with Sweet syndrome. Withdrawal of azathioprine and treatment with oral corticosteroids and colchicine therapy resulted in complete resolution of the rash, although he continued to have high titres of MPO positive ANCA.

Conclusion

Sweet syndrome is a rare adverse reaction to azathioprine but has also been reported to occur in association with ANCA vasculitis. The temporal association with azathioprine in our case and the relatively rapid resolution of the skin vasculitis upon its withdrawal suggested a primarily drug-induced reaction rather than an associated feature of ANCA vasculitis.

Azathioprine Hypersensitivity Syndrome: Two Cases of Febrile Neutrophilic Dermatosis Induced by Azathioprine

Background

Azathioprine is an immunosuppressive agent used in the treatment of immune-mediated diseases. Azathioprine hypersensitivity syndrome is a rare adverse reaction occurring a few days to weeks after the administration of azathioprine.

Case 1

A 36-year-old male with ulcerative colitis presented with erythematous plaques, pustules and erosions on the lower back, buttocks and thighs associated with high fever (39°C) 2 weeks after the initiation of azathioprine 100 mg/day. Additional findings included leukocytosis (18.6 g/L) with neutrophilia (11.1 g/L) and elevated C-reactive protein (128 mg/L). Histopathology showed a dense infiltrate of neutrophils in the hair follicles. We increased the dose of prednisone to 1 mg/kg/day (60 mg/day) and azathioprine was discontinued. He had marked improvement within 3 weeks and did not have any relapse with a 1-year follow-up.

Case 2

A 57-year-old male with ulcerative colitis presented with erythematous plaques and pustules on the lower limbs associated with high fever (40°C) 1 week after the initiation of azathioprine 75 mg/day. Leukocytosis with neutrophilia (13.6 g/L) and elevated C-reactive protein (344 mg/L) were among the laboratory findings. Histopathology showed a dense infiltrate of neutrophils in the hair follicles. The dose of prednisone was increased to 20 mg/day and azathioprine was discontinued, which led to complete remission within 7 days. He did not have any relapse with a 6-month follow-up.

Conclusion

The development of acute neutrophilic dermatitis 2 weeks after the initiation of azathioprine and the complete resolution after its withdrawal were in favor of azathioprine hypersensitivity syndrome. It should not be confused with Sweet syndrome associated with inflammatory bowel disease, as maintenance of azathioprine treatment may lead to life-threatening reactions.

Pyoderma gangrenosum and Sweet syndrome: the prototypic neutrophilic dermatoses

Pyoderma gangrenosum, a dramatic ulcerative skin disease, and Sweet syndrome, a papular dermatosis, were described independently. It was subsequently shown that they share many characteristics, including clinical overlap and the frequent association with multisystemic disorders. The group of the neutrophilic dermatoses encompasses these two dermatoses, as well as other conditions having in common an aseptic neutrophilic infiltrate predominating in the epidermis and/or the dermis and/or the subcutis. Some patients also experience neutrophilic infiltrates in other organs, defining the neutrophilic disease. Recent research suggests that the neutrophilic dermatoses could be considered as the cutaneous expression of the autoinflammation, an aberrant hyperproduction of interleukin-1. Autoinflammation is responsible for monogenic diseases, and is also involved in the mechanism of many polygenic conditions, including the neutrophilic dermatoses.

A case of refractory chronic neutrophilic pustular folliculitis treated with adalimumab

Neutrophilic folliculitis is an often overlooked chronic condition characterized by a monomorphic eruption of "sterile" papulopustules. Neutrophilic folliculitis is often refractory to conventional treatment with topical and systemic antibiotics or isotretinoin. We report a case of severe pustular neutrophilic folliculitis successfully treated with the tumor necrosis factor-alpha inhibitor adalimumab.

[What's new in clinical dermatology?]

L’année 2013 a été l’année des études génétiques de type GWAS (Genome wide association studies) au service de maladies fréquentes (psoriasis et dermatite atopique) visant à identifier des gènes candidats et celles des grandes cohortes de population tirées de registres publics ou privés. Ainsi des corrélations épidémiologiques sont déclinées : psoriasis et surrisque vasculaire, psoriasis et pathologies ORL, rosacée et migraines, acné et habitudes alimentaires, eczéma et carcinome basocellulaire, vitiligo et moindre risque de cancers cutanés, lupus cutané Ro/SS-A et cancer, eczéma chronique et inhibiteurs calciques, pemphigoïde et diurétiques de l’anse. Les liens entre isotrétinoïne et MICI ne sont pas confirmés. Ceux liant azathioprine et cancers cutanés le sont. Des toxidermies nouvelles voient le jour (pigmentations à l’interféron, hypodermites et sarcoïdose aux inhibiteurs de BRAF muté, toxidermies au vandétanib, etc.) et des toxidermies anciennes sont « revisitées » (patch-tests dans les toxidermies sévères, pigmentation à l’hydroxychloroquine, dermatoses neutrophiliques à l’azathioprine). Diane35^® a fait une fausse sortie en janvier 2013 mais le tétrazépam, lui, a fait une vraie sortie en juillet 2013. Des aspects originaux de différentes infections cutanées sont abordés et des données nouvelles sur les MST (méningococcémies et homosexuels masculins, PVH, herpès, syphilis congénitale). Enfin, quelques articles concernant la dermatoscopie, la microscopie confocale et la dermatologie esthétique seront discutés.

Metastatic Crohn's disease: a review and approach to therapy

Metastatic Crohn's disease (CD) is a rare cutaneous manifestation of CD that was first described nearly 50 years ago. Many subsequent reports have defined its most common clinical and histopathologic features. The pathogenesis underlying metastatic CD is unknown but various hypotheses exist. An established standard therapy is lacking. Owing to its rarity and nonspecific clinical presentation along with the diversity of inflammatory skin disorders that often complicate CD, the diagnosis of metastatic CD may be overlooked. This report highlights the salient features of this disorder to facilitate recognition and management of this rare dermatosis.

Association of thiopurine methyltransferase status with azathioprine side effects in Chinese patients with systemic lupus erythematosus

Azathioprine (AZA) is indicated for the treatment of systemic lupus erythematosus (SLE). Thiopurine methyltransferase (TPMT) is the rate-limiting enzyme in the steps of AZA metabolization. Heritable deficiency of TPMT enzyme activity and polymorphisms may lead to leukopenia. This study aims to detect TPMT polymorphisms and TPMT enzyme activity in Chinese SLE patients and to describe the association between TPMT genotypes and adverse effects of AZA. One hundred and twenty-six SLE patients with present or previous thiopurine therapy were identified from a local database. Adverse effects were documented. No TPMT*2, TPMT*3A, or TPMT*3B mutant alleles were detected. TPMT*3C was detected in four patients (3.17 %). The heterozygotes had significantly lower mean TPMT activity as compared to the homozygotes (2.38 ± 1.24 vs. 12.56 ± 7.02 U/mL, P < 0.001). Twenty-seven cases (21.42 %) exhibited adverse effects. All of the heterozygotes (4/4, 100 %) developed severe leukopenia, and three cases (3/4, 75 %) of whom exhibited alopecia simultaneously. The specificity of TPMT*3C for predicting leukopenia and alopecia was 100 and 99.17 %, respectively, and the sensitivity was 28.57 and 60.00 %, respectively. The mean value of TPMT activity with leukopenia (4.67 ± 3.01 vs. 13.2 ± 6.94 U/mL RBC, P < 0.001) or alopecia (2.31 ± 1.16 vs. 12.65 ± 6.98 U/mL RBC, P < 0.001) was significantly lower than those without. TPMT*3C was the most common mutant polymorphism found in the study group. TPMT activity is reduced in TPMT*3C mutant. AZA-induced leukopenia and alopecia were partly correlated to TPMT*3C heterozygotes and low TPMT activity. The results of this study suggest that the value of TPMT genotyping before AZA therapy was limited in Chinese SLE patients, considering the low sensitivity. Routine monitoring of TPMT activity before prescribing and continuous hematological monitoring dose were recommended.