A practical, clinical approach to the assessment and management of suspected insulin allergy

Rituximab Therapy for Insulin Allergy in Type-1 Diabetes Mellitus

Background/Objective

Allergic reactions to insulin have decreased significantly since the introduction of human insulin preparation, but up to 2.4% of insulin-treated patients can still be affected. Rituximab is a monoclonal antibody against the surface antigen CD20 on B lymphocytes, and it is largely used to treat lymphoproliferative and rheumatological conditions. In a very few published case reports, rituximab has been used as an investigational drug to treat severe insulin allergy refractory to conventional therapy. Here, we present an unusual case of a 40-year-old woman with T1DM and severe insulin allergy that was successfully treated with rituximab.

Case Report

The patient was diagnosed with T1DM at age 37. Three years later, skin reactions developed at insulin administration sites. These consisted of pruritic and painful erythema and wheals that appeared within 1 to 4 h of insulin administration, followed by induration, subcutaneous nodules, and surrounding lipodystrophy that lasted several days with spontaneous resolution in 1 to 2 weeks. Extensive immunologic evaluation suggested the reaction was related to insulin allergy. Skin biopsy revealed sublobular panniculitis. After failed conventional treatment with antihistamines, glucocorticoid, and various insulins, rituximab infusion as an investigational approach was initiated. This was very successful, leading to prolonged remission of her insulin allergy.

Discussion

First-line management of insulin allergy should focus on second-generation antihistamines and switching insulin preparation. In refractory cases, systemic immunotherapy with rituximab can be a viable option.

Conclusion

Practitioners should be aware that in patients with insulin allergy who fail conventional treatment, immunotherapy with rituximab can be a viable option.

Chronic spontaneous urticaria preceded by localized insulin reactions: case report

Chronic spontaneous urticaria presents with wheals and/or angioedema for >6 weeks without any specific triggers. The incidence of chronic spontaneous urticaria is increased in patients with comorbid autoimmune conditions. Here, we present a case of chronic spontaneous urticaria in a 9-year-old with type 1 diabetes and autoimmune thyroid disease who first presented with insulin pump site reactions concerning an insulin-related allergy. The patient was successfully treated with antihistamines and later immunosuppression with resumption of insulin pump therapy and remission of chronic spontaneous urticaria symptoms 18 months after onset.

Case Report: Insulin hypersensitivity in youth with type 1 diabetes

Objective

Immediate type I, type III, and delayed type IV hypersensitivity reactions to insulin are rare, but potentially serious complications of exogenous insulin administration required for the treatment of type 1 diabetes (T1D).

Methods

We present four cases of insulin hypersensitivity reactions occurring in youth with T1D and a literature review of this topic.

Results

Insulin hypersensitivity reactions included types I, III, and IV with presentations ranging from localized urticaria, erythematous nodules, and eczematous plaques to anaphylaxis with respiratory distress. Reactions occurred in youth with newly diagnosed T1D and in those with long-standing T1D who were using both injection and insulin pump therapy. Multidisciplinary care involving pediatric endocrinology and allergy/immunology utilizing trials of many adjunct therapies yielded minimal improvement. Despite the use of various treatments, including antihistamines, topical therapies, immunosuppressant medications, desensitization trials, and intravenous immune globulin, cutaneous reactions, elevated hemoglobin A1c levels, and negative effects on quality of life remain persistent challenges. One patient became one of the youngest pancreas transplant recipients in the world at age 12 years due to uncontrollable symptoms and intolerable adverse effects of attempted therapies.

Conclusion

Although rare, insulin hypersensitivity reactions negatively affect glycemic control and quality of life. These cases demonstrate the varying severity and presentation of insulin hypersensitivity reactions along with the limited success of various treatment approaches. Given the life-sustaining nature of insulin therapy, further studies are needed to better understand the underlying pathophysiology of insulin hypersensitivity and to develop targeted treatment approaches.

Insulin allergy manifesting soon after COVID-19 vaccination (BNT162b2)

We experienced a case with insulin allergy which manifested soon after COVID-19 vaccination.

Insulin allergy: a diagnostic and therapeutic strategy based on a retrospective cohort and a case-control study

AIMS/HYPOTHESIS

Insulin allergy is a rare but significant clinical challenge. We aimed to develop a management workflow by (1) validating clinical criteria to guide diagnosis, based on a retrospective cohort, and (2) assessing the diagnostic performance of confirmatory tests, based on a case-control study.

METHODS

In the retrospective cohort, patients with suspected insulin allergy were classified into three likelihood categories according to the presence of all (likely insulin allergy; 26/52, 50%), some (possible insulin allergy; 9/52, 17%) or none (unlikely insulin allergy; 17/52, 33%) of four clinical criteria: (1) recurrent local or systemic immediate or delayed hypersensitivity reactions; (2) reactions elicited by each injection; (3) reactions centred on the injection sites; and (4) reactions observed by the investigator (i.e. in response to an insulin challenge test). All underwent intradermal reaction (IDR) tests. A subsequent case-control study assessed the diagnostic performance of IDR, skin prick and serum anti-insulin IgE tests in ten clinically diagnosed insulin allergy patients, 24 insulin-treated non-allergic patients and 21 insulin-naive patients.

RESULTS

In the retrospective cohort, an IDR test validated the clinical diagnosis in 24/26 (92%), 3/9 (33%) and 0/14 (0%) likely, possible and unlikely insulin allergy patients, respectively. In the case-control study, an IDR test was 80% sensitive and 100% specific and identified the index insulin(s). The skin prick and IgE tests had a marginal diagnostic value. Patients with IDR-confirmed insulin allergy were treated using a stepwise strategy.

CONCLUSIONS/INTERPRETATION

Subject to validation, clinical likelihood criteria can effectively guide diabetologists towards an insulin allergy diagnosis before undertaking allergology tests. An IDR test shows the best diagnostic performance. A progressive management strategy can subsequently be implemented. Continuous subcutaneous insulin infusion is ultimately required in most patients.

CLINICALTRIALS

gov: NCT01407640.

Identification of Effective and Nonpromiscuous Antidiabetic Drug Molecules from Penicillium Species

Diabetes mellitus (DM) is a very common metabolic disorder/disease. The deterioration of β-cells by autoimmune system is the hallmark of this disease. Thioredoxin-Interacting Protein (TXNIP) is responsible for β-cells degradation by T-cells in the pancreas. This protein had been declared a good drug target for controlling DM. Lots of side effects have been reported as a result of long-time consumption of conventional antidiabetic drugs. The development of new and effective drugs with the minimal side effects needs time. TXNIP was selected as a target for Computer-Aided Drug Design. The antidiabetic fungal metabolite compounds were selected from the literature. The compounds were screened for their drug-likeness properties by DruLiTo and DataWarior tools. Twenty-two drug-like fungal compounds were subjected to Quantitative Structure-Activity Relationship (QSAR) analysis by using CheS-Mapper 2.0. The lowest (0.01) activity cliff was found for three compounds: Pinazaphilone A, Pinazaphilone B, and Chermesinone A. The highest value for apol (81.76) was shown by Asperphenamate, while Albonoursin and Sterenin L showed highest score (40.66) for bpol. The lowest value (0.46) for fractional molecular frame (FMF) was calculated for Pinazaphilone A and Pinazaphilone B. TPSA for Pinazaphilone A and Pinazaphilone B was 130.51 Å2. $\log P<5$ was observed for all the twenty-two compounds. Molecular docking of fungal compounds with TXNIP was done by AutoDock Vina. The binding energy for complexes ranged between −9.2 and −4.6 kcal/mol. Four complexes, TXNIP-Pinazaphilone A, TXNIP-Pinazaphilone B, TXNIP-Asperphenamate, and TXNIP-Sterenin L, were selected for MD simulation to find out the best lead molecule. Only one complex, TXNIP-Pinazaphilone B, showed a stable conformation throughout the 80 ns run of MD simulation. Pinazaphilone B derived from the Penicillium species fungi was selected as the lead molecule for development of antidiabetic drug having the least side effects.

Insulin Allergy to Detemir Followed by Rapid Onset of Diabetic Ketoacidosis: A Case Report and Literature Review

The management of diabetes mellitus in an insulin-dependent patient is challenging in the setting of concomitant antibody-mediated-insulin hypersensitivity. We report a case of a 62-year-old woman with pre-existing type 2 diabetes mellitus of 10 years duration who developed type 3 hypersensitivity reaction to insulin analogue detemir, and subsequently, severe diabetic ketoacidosis (DKA). She was C-peptide negative and was diagnosed with insulin-dependent diabetes. Despite increasing dose adjustments, insulin-meal matching, and compliance with insulin, she experienced episodes of unexpected hyperglycaemia and hypoglycaemia. The development of rash after detemir initiation and rapid progression to DKA suggests an aberrant immune response leading to the insulin allergy and antibody-induced interference with insulin analogues. Glycaemic control in the patient initially improved after being started on subcutaneous insulin infusion pump with reduced insulin requirements. However, after a year on pump therapy, localised insulin hypersensitivity reactions started, and glycaemic control gradually deteriorated.

The complexities of insulin allergy: a case and approach

Background

Insulin hypersensitivity is rare, but challenging for individuals with diabetes. The prevalence of insulin allergy has decreased since the introduction of human recombinant insulin preparations. Hypersensitivity reactions range from injection site erythema and swelling, to anaphylaxis. While some reactions are to excipients (zinc, protamine, metacresol), many are to recombinant insulin itself. We present a case of type 1 hypersensitivity to various preparations of insulin in a patient with insulin-dependent type 2 diabetes mellitus (T2DM).

Case presentation

A 61-year-old woman with a 30-year history of insulin-dependent T2DM was referred for evaluation of reactions to insulin. She had two episodes over 5-months; both required Emergency Department visits and epinephrine administration. The first episode entailed a burning sensation of the extremities and nausea, immediately after injecting NovoRapid^® insulin. The second event entailed a similar reaction but this time there was also angioedema of the upper airway with difficulty breathing and hypotension, immediately after injecting Levemir^® and NovoRapid^®, and taking metformin. There were no cofactors such as exercise, infectious illness, or NSAIDs use. Skin testing was performed with metformin, Lantus^®, Humalog^®, NovoRapid^®, glulisine, insulin regular, NPH, Levemir^® and the excipient protamine, as per published testing concentrations. Metacresol was not tested as its use was restricted by the hospital pharmacy. Insulin preparations with and without metacresol were included in testing however. A clinic staff served as a negative control. The patent had negative testing with protamine, but sensitization to all insulin preparations. Metformin skin testing and challenge along with latex IgE were negative. Subsequently, she underwent intentional weight loss of 70 lb, and was started on oral hypoglycemics with good effect.

Conclusions

Our case highlights the importance of diagnosing insulin allergy through a detailed history and focused testing. Therapeutic strategies include avoidance and insulin alternatives, alternate insulin preparations, or desensitization. In severe recurrent hypersensitivity reactions, Omalizumab or pancreatic transplantation have been effective.

Ambulatory intravenous insulin and islet cell transplantation to treat severe type III insulin hypersensitivity in a patient with type 1 diabetes mellitus

Allogenic pancreatic islet cell transplantation is an appropriate treatment option to consider in the management of refractory cases of severe hypersensitivity to insulin in patients with type 1 diabetes mellitus.

Exogenous recombinant human insulin-induced severe hypersensitivity reaction precipitating hyperglycemic crisis: A clinical conundrum

Hypersensitivity reactions against exogenous insulin are a rare clinical entity after the advent of recombinant human insulin; however, there are still case reports wherein patients develop hypersensitivity reactions against insulin. We present the case of a type 1 diabetes mellitus patient who developed type 1 hypersensitivity reaction against subcutaneous insulin. He had recurrent episodes of diabetic ketoacidosis after developing hypersensitivity reactions against insulin, requiring multiple hospital admissions. When he presented to us, he was on both insulin infusion and subcutaneous insulin, requiring a daily insulin dose of about 800 units and having severe insulin hypersensitivity reactions and hyperglycemia. He had multiple subcutaneous erythematous nodules at the insulin injection sites, however, had no evidence of systemic allergy. Investigations revealed eosinophilic leukocytosis, and high IgE levels and skin biopsy showing evidence of insulin hypersensitivity. He was desensitized to insulin according to Heinzerling et al. insulin desensitization protocol and subsequently with immunomodulation therapy using steroids (pulse methylprednisolone) and mycophenolate mofetil as well as by installation of insulin pump.

RAPID DESENSITIZATION WITH INTRAVENOUS INSULIN IN A PATIENT WITH DIABETIC KETOACIDOSIS AND INSULIN ALLERGY

OBJECTIVE

We report a case of insulin desensitization in a patient with known allergy to multiple insulin preparations who presented with diabetic ketoacidosis (DKA).

METHODS

Clinical and laboratory data, and desensitization protocols are presented.

RESULTS

A 65-year-old woman with type 2 diabetes and a documented insulin allergy presented with severe DKA. She was managed initially with intravenous (IV) fluids, sodium bicarbonate, and hemodialysis. An intradermal skin test was positive for 0.01 units/mL of human regular insulin. A rapid desensitization protocol for IV human regular insulin was initiated after pretreatment with methylprednisolone, ranitidine, montelukast, and cetirizine. An initial dilution of 1 unit of insulin in 100,000 mL of 0.9% sodium chloride was started at 5 mL/hour IV. The dilution was increased at 60-minute intervals to 1 unit/10,000 mL, 1 unit/1,000 mL, 1 unit/100 mL, 1 unit/10 mL, then 1 unit/1 mL. The dose was then increased from 1 to 7 units/hour (0.1 units/kg body weight/hour). The anion gap closed after 24 hours, and overlapping desensitization was started for subcutaneous (SC) human regular insulin starting with 0.00001 units with a gradual increase to 7 units before meals and 6 units at bedtime over 5 days. There were no anaphylactic reactions to IV or SC insulin. She was discharged with human regular insulin SC 4 times daily, oral montelukast, cetirizine, diphenhydramine as needed, and an epinephrine pen. No allergic reactions were reported at follow-up visits.

CONCLUSION

Rapid insulin desensitization is possible to allow treatment of DKA with human regular insulin IV in patients with known insulin allergy.

Cutaneous Adverse Effects of Diabetes Mellitus Medications and Medical Devices: A Review

Diabetes mellitus is one of the most prevalent chronic diseases in the USA. If uncontrolled, diabetes can lead to devastating complications. Diabetes medications and medical devices largely contribute to the significant financial expense that the disease inflicts on affected individuals and society. Alongside significant economic burden, there are numerous cutaneous adverse effects associated with diabetes medications and medical devices. Despite the large and increasing number of individuals living with diabetes and the wide use of the related medications and medical devices, there is limited literature that comprehensively documents their cutaneous adverse effects. These cutaneous adverse effects are significant as they can worsen glycemic control, increase disease distress, and may increase risk of associated complications. Thus, it is important that providers can recognize these cutaneous adverse effects, identify the culprit agents, and can properly manage them. In this article, we provide a critical review of the cutaneous adverse effects of medications and devices used in the management of diabetes and provide insight into risk factors and prevention and an overview of therapeutic management. An emphasis is placed on clinical recognition and treatment for use of the medical providers who, regardless of practice setting, will treat patients with diabetes.

Insulin allergy can be successfully managed by a systematic approach

Background

Type I insulin allergy can be a challenging condition, and there is no international consensus on how to establish the diagnosis. Measurement of specific IgE and skin testing have been cornerstones in the diagnostic work-up. However, these tests have limitations, mainly lack of correlation between test results and clinical findings. At the Allergy Centre, Odense University Hospital, patients with suspected insulin allergy have been evaluated since 2003. The aim of this study was to establish a systematic approach to diagnose and treat patients with insulin allergy.

Methods

The study was conducted retrospectively by retrieving data from the Allergy Centre database on patients with suspected insulin allergy evaluated from 2003 to 2017. The examination comprised a comprehensive medical history, specific IgE against insulin and intracutaneous tests (ICT) with different insulins.

Results

A total of 144 patients were examined on suspicion of insulin allergy of which 110 had negative specific IgE in serum. Of the remaining 34 patients, 33 had ICT performed; 2 had negative ICTs, while 31 had one or more positive ICT. All 34 patients had mild symptoms, and 4 could obtain symptom relief with antihistamines or local steroids, 9 could be managed with oral antidiabetics, and 7 were switched to other insulins. The final 14 patients were offered an insulin pump because of reactions to many different insulins, many positive ICTs, unmanageable diabetes, young age and compliance, or convenience.

Conclusion

Insulin allergy can be managed by a systematic approach, and symptom relief is obtainable in most patients.

Severe allergic reaction to human insulin in the patient with diabetic ketoacidosis

Diabetic ketoacidosis (DKA) is an acute and major life-threatening complication of diabetes mellitus. Fluid resuscitation, insulin therapy, and electrolyte replacement are essential for DKA treatment. Rarely, life threatening allergic reactions might develop in a patient treated with insulin. If anaphylaxis develops after insulin, the DKA treatment options are restricted. A limited number of case reports have been reported in patients with severe anaphylactic reactions to human insulin who were then treated with synthetic insulin analogues. We present a case of a 45-year-old male patient with allergic reactions to human insulin. The patient was successfully treated with insulin aspart and hemodialysis.

Allergic myocardial infarction following recombinant human insulin

BACKGROUND

Allergic myocardial infarction is a rare clinical entity.

OBJECTIVES

Although a few number of case reports with severe anaphylactic reactions to recombinant human insulin have been reported, allergic myocardial infarction, known as Kounis Syndrome, has not been reported before.

METHODS

Herein, we report a 57-year-old woman with myocardial infarction, referred for urticarial rash, chest pain, and palpitations developed after the first subcutaneous dose of recombinant human insulin.

RESULTS

The patient treated with antihistamines and steroids and discharged from hospital in a good condition.

CONCLUSIONS

Physicians should be aware of allergic myocardial infarction. The diagnosis of Kounis Syndrome should be entertained when allergic symptoms, electrocardiographic changes, and high cardiac enzymes accompany acute-onset chest pain. All patients admitted to the emergency department with chest pain and ST elevation on electrocardiography should be asked about allergic insults.

Hypersensitivity reactions to human insulin analogs in insulin-naïve patients: a systematic review

OBJECTIVE

The objective of this study was to raise awareness of hypersensitivity reactions to human insulin analogs (HIAs) in insulin-naïve patients and encourage consistent and detailed reporting of HIA reactions.

DATA SOURCES

A search of PubMed, MEDLINE and International Pharmaceutical Abstracts using the terms 'insulin' and 'hypersensitivity' was completed with English language, humans, and publication date after 1 January 1990 as limits.

STUDY SELECTION AND DATA EXTRACTION

The initial search identified 598 articles. These titles and abstracts were reviewed for relevance (e.g. mention of HIA) resulting in the exclusion of 477 articles. The full texts of the remaining titles were evaluated in addition to each article's references to identify additional reports meeting criteria (n = 14). Upon extensive review, 118 articles were excluded for not meeting prespecified inclusion criteria, resulting in 17 articles.

DATA SYNTHESIS

Evidence supporting hypersensitivity reactions to HIAs was variable, potentially due to a variety of causes (e.g. difficulty identifying a true case of hypersensitivity reaction to HIAs). Inconsistencies were noted for the identification, confirmatory testing, management, and reporting of these reactions. Management strategies included use of insulin desensitization protocols, antihistamines, steroids, immunosuppressant/immunomodulator therapies, conversion to noninsulin therapies, and pancreas transplantation.

CONCLUSIONS

Complete and consistent identification, evaluation, management, and reporting of these reactions is essential. Specific aspects of the patient's history should be reported, including previous insulin exposure, the specific HIAs used, duration of use prior to the reaction, a clear timeline of the reaction, and discussion of precipitating events or confounding factors.

Long-acting insulin allergy in a diabetic child

Insulin allergy has been uncommon since the introduction of human recombinant insulin preparations; the prevalence is 2.4%. Insulin injection could elicit immediate reactions, which are usually induced by an IgE-mediated mechanism, within the first hour after drug administration. In the present study, we describe the case of a child who experienced immediate urticaria after long-acting insulin injection. A 9-year-old girl affected by type I diabetes mellitus referred a history of three episodes of urticaria 30 min after insulin subcutaneous injection. During the first week of insulin therapy, she developed generalized immediate urticaria twice after long-acting insulin glargine first and then once after insulin degludec administration. Symptoms resolved within a few hours after treatment with oral antihistamine. She tolerated rapid insulin lispro. Her personal allergological history was negative. Skin prick tests with degludec, glargine and detemir were performed, showing negative results. Intradermal 1:100000-diluted tests were immediately positive for both degludec and glargine but not for detemir. In light of these findings, detemir was administered without any reaction. Our results show that detemir is tolerated by patients with clinical hypersensitivity reactions to degludec and glargine. Although reactions could be attributable to additives allergy, such as zinc or metacresol, this was excluded since all three preparations contain the same components. So, insulin itself acted as offending allergen. Detemir differs from degludec and glargine in a few aminoacids. Therefore, it is possible that the conformational rather than the linear epitope may be responsible for the reaction. This result suggests integrating intradermal tests in the diagnostic flowchart for insulin allergy. Insulin allergy should always be suspected in patients with immediate symptoms after drug injection. As allergologic work-up, prick by prick test and intradermal test to insulin preparations should be performed. In case of negative results of cutaneous tests, insulin analogs may be administered.

A case of insulin allergy successfully managed using multihexamer-forming insulin degludec combined with liraglutide

BACKGROUND

Insulin allergy, one of insulin's adverse effects, is rare, especially in patients with Type 2 diabetes, but management is difficult and no effective strategy has yet been established. We experienced an insulin allergy case successfully managed with a novel combination of insulins.

CASE REPORT

A 38-year-old woman started insulin therapy when diabetes was diagnosed at age 19 years. Despite poorly controlled diabetes because of poor adherence, she hoped to conceive a child and continuous subcutaneous insulin infusion was introduced using insulin aspart at age 32 years. One month thereafter, she developed skin reactions at the subcutaneous insulin infusion catheter insertion site. The patient was then tested for all rapid-acting insulin formulations, all of which triggered local reactions. She decided to continue the continuous subcutaneous infusion of human regular insulin, accompanied by oral cetirizine hydrochloride and betamethasone valerate ointment. The patient was admitted to our hospital at age 38 years with high HbA_1c levels. She was tested for all long-acting insulin analogues. All results, except for insulin degludec, were positive. She discontinued continuous subcutaneous insulin infusion and switched to insulin degludec combined with liraglutide. The allergic reactions had completely disappeared and her blood glucose was well controlled by the time of discharge.

CONCLUSION

Our patient was allergic to all insulin formulations except insulin degludec. Her allergic reactions completely disappeared after switching to insulin degludec. The crystallized structure of this insulin might mask its skin allergen antigenicity. Furthermore, her postprandial hyperglycaemia was successfully controlled with liraglutide. We propose multihexamer-forming ultra-long-acting insulin plus glucagon-like peptide-1 analogues as a therapeutic option for patients with insulin allergy.

Insulin Allergy

Objective: A case of insulin allergy to insulin aspart, insulin aspart protamine/insulin aspart 70/30, insulin lispro, and insulin lispro protamine/insulin lispro 75/25 in a patient with type 2 diabetes mellitus is reported. Case Summary: A 76-year-old Caucasian male weighing 81 kg presented with complaints of burning, lumps, and a rash where his insulin aspart protamine/insulin aspart 70/30 was injected 2 months after initiation. Because poor injection technique can mimic insulin allergy, the patient was counseled again on proper injection technique. The patient presented 2 weeks later with the same complaints. Insulin aspart protamine/insulin aspart 70/30 was discontinued and insulin lispro protamine/insulin lispro 75/25 was initiated. The patient presented 3 months later with a localized reaction. Insulin lispro protamine/insulin lispro 75/25 was discontinued and insulin U100 glargine and insulin lispro were initiated. One week later, the patient still had complaints of a localized reaction and was referred to an allergist for testing. Skin prick tests revealed insulin allergy to insulin aspart and insulin lispro but not to insulin U100 glargine or insulin glulisine. The patient’s regimen was changed to insulin U100 glargine and insulin glulisine, and he has not experienced any reaction since. Discussion: Allergic reactions to human insulin preparations are rare and may present as a localized reaction or a generalized reaction. Different types of allergic reactions to human insulin have been reported, including type I, type III, and type IV hypersensitivity reactions. If insulin allergy is suspected, the following steps should be taken to confirm such allergy: evaluation of injection technique, switching to a different insulin preparation, and referral to an allergist for allergy testing if necessary. Conclusion: A patient with type 2 diabetes mellitus experienced a type I hypersensitivity reaction to insulin aspart, insulin aspart protamine/insulin aspart 70/30, insulin lispro, and insulin lispro protamine/insulin lispro 75/25.

Faulty Injection Technique: A Preventable But Often Overlooked Factor in Insulin Allergy

Insulin hypersensitivity-a rare occurrence with currently available insulin preparations-may have varied manifestations, ranging from a local injection site allergy to severe generalized anaphylactic reactions. While various additives included in commercial insulin preparations and insulin peptides themselves remain the primary allergens responsible, faulty injection technique may at times potentiate the development of insulin allergy. Management of insulin allergy is complex, potentially dangerous at times, and can be challenging for the treating physician. We report a case of insulin allergy due to intradermal insulin injections which was cured by adopting a proper injection technique.

Two Cases of Allergy to Insulin in Gestational Diabetes

Allergic reaction to insulin is uncommon since the introduction of human recombinant insulin preparations and is more rare in pregnant than non-pregnant females due to altered immune reaction during pregnancy. Herein, we report two cases of allergic reaction to insulin in gestational diabetes that were successfully managed. One case was a 33-year-old female using isophane-neutral protamine Hagedorn human insulin and insulin lispro. She experienced dyspnea, cough, urticaria and itching sensation at the sites of insulin injection immediately after insulin administration. We discontinued insulin therapy and started oral hypoglycemic agents with metformin and glibenclamide. The other case was a 32-year-old female using insulin lispro and insulin detemer. She experienced pruritus and burning sensation and multiple nodules at the sites of insulin injection. We changed the insulin from insulin lispro to insulin aspart. Assessments including immunoglobulin E (IgE), IgG, eosinophil, insulin antibody level and skin biopsy were performed. In the two cases, the symptoms were resolved after changing the insulin to oral agents or other insulin preparations. We report two cases of allergic reaction to human insulin in gestational diabetes due to its rarity.