Azathioprine hypersensitivity reaction in a patient with ulcerative colitis

Three hospital admissions in 9 days to diagnose azathioprine hypersensitivity in a patient with Crohn's disease

Azathioprine (AZA) is commonly used as a steroid-sparing immunosuppressive medication for the treatment of immune-mediated disorders including Crohn's disease. There is ample awareness of the more common adverse effects of this drug, including myelosuppression and risk of malignancy. We present a case of a 57-year-old man with fistulizing Crohn's disease who underwent 3 hospital admissions for recurrent fever with an extensive work-up for infection before the diagnosis of AZA hypersensitivity was made. Clinicians should be vigilant for AZA hypersensitivity as a cause of otherwise unexplained fever. Furthermore, in patients with inflammatory bowel disease (IBD), the signs and symptoms of AZA hypersensitivity may overlap with typical findings of inflammatory bowel disease flare.

Azathioprine-induced fever in autoimmune hepatitis

Underdiagnosis of drug-induced fever leads to extensive investigation and prolongation of hospitalization, and may lead to multiple unnecessary invasive procedures and a wrong diagnosis. Azathioprine is a widely used immunosuppressive drug. We report a case of a 53-year-old female patient diagnosed with autoimmune hepatitis treated with azathioprine, who presented to the emergency room with a 6-wk history of fever and chills without other associated symptoms. Since the patient’s fever was of unknown origin, she was hospitalized. All treatment was stopped and an extensive workup to explore the source of fever and chills was performed. Results of chest X-ray, viral, urine, and blood cultures, autoimmune serology, transthoracic and transesophageal echocardiography, and abdominal ultrasound revealed no source of infection. A rechallenge test of azathioprine was performed and the fever and chills returned within a few hours. Azathioprine was established as the definite cause following rechallenge. Fever as an adverse drug reaction is often unrecognized. Azathioprine has been reported to cause drug-induced fever in patients with inflammatory bowel disease, rheumatoid arthritis, and sarcoidosis. To the best of our knowledge there have been no previous reports documenting azathioprine-induced fever in patients with autoimmune hepatitis. The occurrence of fever following the readministration of azathioprine suggests the diagnosis of drug-induced fever, particularly after the exclusion of other causes. A careful rechallenge is recommended to confirm the diagnosis.

Azathioprine hypersensitivity presenting as sweet syndrome in a child with ulcerative colitis

Sweet syndrome is a cutaneous lesion characterized by tender, red inflammatory nodules or papules. We describe a pediatric case of Sweet syndrome presenting 10 days after treatment with azathioprine. As azathioprine is widely used in children with inflammatory bowel disease, clinicians should be aware of this unusual adverse reaction.

The cutaneous and systemic manifestations of azathioprine hypersensitivity syndrome

BACKGROUND

Azathioprine (AZA) hypersensitivity syndrome is a rare side effect that typically occurs early in the initiation of therapy and may include a cutaneous eruption. It is often under-recognized because it mimics infection or disease exacerbation. Until recently, the cutaneous findings associated with AZA hypersensitivity have been reported using nonspecific, descriptive terms without a supportive diagnostic biopsy.

OBJECTIVE

To characterize the cutaneous and histologic findings associated with AZA hypersensitivity syndrome.

METHODS

We conducted a retrospective analysis of two cases of AZA hypersensitivity syndrome and describe the cutaneous manifestations and histological findings of each case. A review of the English literature for cases of AZA hypersensitivity or allergic or adverse reactions associated with AZA was performed.

RESULTS

Sixty-seven cases of AZA hypersensitivity were reviewed; 49% (33/67) had cutaneous manifestations. Of those cases presenting with cutaneous findings, 76% (25/33) had biopsy results or clinical features consistent with a neutrophilic dermatosis, whereas the other 24% (8/33) were reported as a nonspecific cutaneous eruption.

LIMITATIONS

Only case reports in which the skin findings could be classified were reviewed.

CONCLUSIONS

The predominant cutaneous reaction reported in the literature and observed in the present case series is a neutrophilic dermatosis. Hypersensitivity to AZA can manifest along a wide clinical spectrum from local neutrophilic disease to a systemic syndrome. Skin findings may be an important early clue to the diagnosis of AZA hypersensitivity and aid in prompt recognition and treatment of this potentially life-threatening adverse drug effect.

EPONYM. Sweet syndrome

Sweet syndrome, also referred to as acute febrile neutrophilic dermatosis, is characterized by tender, red inflammatory nodules or papules that occur in association with infection, malignancy, connective tissue disease, or following exposure to certain drugs. Although drug-induced Sweet syndrome is rare, granulocyte colony-stimulating factor, all-trans-retinoic acid, and miscellaneous drugs have been implicated in causing this disorder in adults. In pediatric patients, granulocyte colony-stimulating factor, all-trans-retinoic acid, trimethoprim-sulfamethoxazole, and azathioprine have been implicated as potential causes of drug-induced Sweet syndrome. To date, six cases, including the patient reported here, have been reported in children.

Sweet syndrome as a manifestation of azathioprine hypersensitivity

Sweet syndrome is a reactive, sterile, pustular dermatosis that occurs in association with infection, malignancy, or connective tissue disease or in response to the use of certain medications. Sweet syndrome secondary to azathioprine therapy is rarely reported. We describe 3 patients, 2 with inflammatory bowel disease and 1 with myasthenia gravis, who developed febrile pustulosis consistent with Sweet syndrome 1 to 2 weeks after treatment with azathioprine. Antibiotic therapy failed in all patients, but Sweet syndrome resolved with drug withdrawal and prednisone therapy. Because azathioprine is widely used, clinicians should be aware of this adverse reaction.

Azathioprine in dermatology: The past, the present, and the future

For several decades, dermatologists have utilized azathioprine to treat numerous debilitating skin diseases. This synthetic purine analog is derived from 6-mercaptopurine. It is thought to act by disrupting nucleic acid synthesis and has recently been found to interfere with T-cell activation. The most recognized uses of azathioprine in dermatology are for immunobullous diseases, generalized eczematous disorders, and photodermatoses. In this comprehensive review, the authors present recent advancements in the understanding of azathioprine and address aspects not covered in prior reviews. They (1) summarize the history of azathioprine; (2) discuss metabolism, integrating information from recent publications; (3) review the mechanism of action with attention paid to the activities of azathioprine not mediated by its 6-mercaptopurine metabolites and review new data about inhibition by azathioprine of the CD28 signal transduction pathway; (4) thoroughly examine thiopurine s-methyltransferase genetics, its clinical relevance, and interethnic variations; (5) review prior uses of azathioprine in the field of dermatology and grade the level of evidence; (6) discuss the use of azathioprine in pregnancy and pediatrics; review (7) key drug interactions and (8) adverse effects; (9) suggest a dosing and monitoring approach different from prior recommendations; and (10) explore the future of azathioprine, focusing on laboratory considerations and therapeutic application.

Severe muscular weakness: an unusual adverse effect of azathioprine therapy

Azathioprine, an analog of 6-mercaptopurine has been used as a steroid-sparing agent in the treatment of inflammatory bowel disease for over 30 years. Hypersensitivity reactions to azathioprine including fever, myalgia, arthralgia, rash are well documented in the literature. Here, we report 2 cases of azathioprine hypersensitivity in patients with inflammatory bowel disease manifesting with the unusual symptom of profound muscular weakness resulting in inability to perform simple tasks such as lifting even light objects, sitting upright, and walking a few steps. Development of severe weakness raised concern about myositis, rhabdomyolysis, myopathy, and sepsis in these patients. Discontinuation of azathioprine resulted in prompt improvement of muscular weakness, and rechallenge led to recurrence of similar symptoms within hours. These observations suggest that the development of muscular weakness in patients on azathioprine should be considered as an adverse effect of the drug. Failure to recognize this adverse outcome can lead to prolonged periods of muscular weakness in this group of patients.

Drug eruption caused by azathioprine: value of using the drug-induced lymphocytes stimulation test for diagnosis

Azathioprine (AZA) is an immunosuppressant commonly used for organ transplantation and autoimmune diseases. Allergic side effects of AZA are rare, and reported allergic skin eruptions from AZA are very limited in Japan. We report AZA-induced drug eruption that developed in two cases of systemic scleroderma with polymyositis. One case presented with Stevens-Johnson syndrome, and the other had systemic papular erythema. The stimulation indices of the drug-induced lymphocyte stimulation test (DLST) for AZA in these two patients were as high as 2,180% and 430%, respectively, but those of healthy volunteers were under 120% without nonspecific suppression of lymphocyte proliferation. Other drugs used simultaneously were ruled out by patch and challenge tests. The challenge test for Stevens-Johnson syndrome type drug allergy is very risky. DLST is a good diagnostic tool for AZA allergy, especially for severe drug allergy cases.

Diffuse febrile dermatosis in a patient with active ulcerative colitis under treatment with steroids and azathioprine: a case of Sweet's syndrome. Case report and review of literature

Ulcerative colitis is an inflammatory bowel disease often associated with extra-intestinal manifestations, such as dermatological disorders. Of these, the most frequent are erythema nodosum and pyoderma gangrenosum, the two neutrophilic forms of dermatosis. Another is Sweet' s syndrome, which results in a sudden eruption of tender, raised erythematous or violaceous plaques/papules or nodules, less frequent vesicles, pustules or bullae, involving face, neck, arms and trunk. This skin disorder is frequently observed in patients with leukaemia or connective tissue diseases, while it is very rare in patients with inflammatory bowel disease. The present report deals with the case of a febrile diffuse skin eruption in a 53-year-old patient with moderately active ulcerative colitis after few days' treatment with steroids and azathioprine. At first, the dermatosis was addressed to an idiosyncrasy to azathioprine, which was, therefore, promptly discontinued. Histological examination of skin biopsies revealed the presence of features typical of a Sweet's syndrome. The eruption gradually improved as well as the patient's general condition, until complete regression was achieved following steroid treatment.

Thioguanine: a potential alternate thiopurine for IBD patients allergic to 6-mercaptopurine or azathioprine

OBJECTIVE

Approximately 10% of inflammatory bowel disease (IBD) patients receiving 6-mercaptopurine (6-MP) or azathioprine (AZA) develop drug hypersensitivity reactions necessitating early discontinuation of these traditional thiopurines. These allergic reactions typically reoccur upon rechallenge. Our recently published pilot study suggested that thioguanine (6-TG), a closely related thiopurine, was efficacious and well tolerated in IBD patients resistant to 6-MP/AZA. The aim of this study was to determine if hypersensitivity reactions to 6-MP/AZA reoccur with 6-TG therapy.

METHODS

IBD patients allergic to 6-MP and/or AZA were treated with 6-TG as an alternate thiopurine. Hypersensitivity reactions to 6-MP/AZA must have been documented within 6 wk of 6-MP/AZA initiation.

RESULTS

6-TG was initiated in 21 IBD patients at a median (range) dose of 20 (10-40) mg/day. 6-TG hypersensitivity reaction occurred in only four of 21 (19%) patients after a median time interval of 9 days. Pancreatitis did not reoccur with 6-TG. Eighty-two percent of 6-TG tolerant patients were assessed as improved at last follow-up.

CONCLUSIONS

These results suggest that 6-TG may be considered as a possible alternate thiopurine in patients allergic to traditional 6-MP/AZA. Despite these favorable results, candidates for 6-TG should be selected with caution, and its use should be reserved for IBD patients well informed about potential toxicities.

Azathioprine or methotrexate in the treatment of patients with steroid-dependent or steroid-resistant ulcerative colitis: results of an open-label study on efficacy and tolerability in inducing and maintaining remission

BACKGROUND

The role of azathioprine and methotrexate in inducing and maintaining remission in patients with ulcerative colitis is still controversial.

AIM

To evaluate the efficacy and tolerability of these two drugs in a series of patients with steroid-dependent or steroid-resistant active ulcerative colitis.

METHODS

Forty-two patients were treated with a daily dose of azathioprine (2 mg/kg) and, if intolerant or not responding, with methotrexate (12.5 mg/week intramuscularly), and their efficacy was established by clinical, endoscopic and histological examinations at 6 months. Patients achieving clinical remission continued with treatment and were followed up.

RESULTS

Of the 42 patients on azathioprine, 10 experienced early side-effects requiring withdrawal from treatment, 22 (69%) achieved complete remission, six (19%) achieved improvement and four (12%) obtained no substantial benefit. Methotrexate, administered to eight patients intolerant to and two patients resistant to azathioprine, induced complete remission in six patients (60%) and improvement in four (40%). During follow-up, a larger number of patients on azathioprine relapsed in comparison with patients on methotrexate [16/28 (57%) vs. 2/10 (20%), respectively; P < 0.05]. Only minor side-effects were observed on both treatments.

CONCLUSIONS

Azathioprine is effective in patients with steroid-dependent or steroid-resistant ulcerative colitis. Methotrexate seems to be a good alternative in patients intolerant to or not responding to azathioprine.

Medical therapy for ulcerative colitis

Although newer therapeutic agents are being developed for the treatment of inflammatory bowel disease, aminosalicylates and corticosteroids remain the mainstay of treatment for UC (Tables 2-5). Patients who do not respond to these agents or become steroid dependent require immunomodulatory therapy or curative surgery. Cyclosporine represents the greatest treatment advance for UC in 10 years. The role of nicotine, heparin, antibiotics, probiotics, and SCFA in the treatment of UC is less clear, but these agents may offer an alternative therapeutic approach for patients intolerant or nonresponsive to standard therapy.