The necessity of patch testing in determining the causative drug of AGEP

Rare acute generalized exanthematous pustulosis caused by iodixanol: A case report

RATIONALE

Acute generalized exanthematous pustulosis (AGEP) is a rare delayed allergic reaction, which is mostly caused by drugs, but there are few reports of iodixanol in particular. At present, 4 cases induced by iodixanol have been reported in the literature, but none have been reported in China.

PATIENT CONCERNS

In this report, we report a case of AGEP induced by intravenous bolus infusion of iodixanol during multislice spiral CT enhanced scanning of the whole abdomen in a patient with rectal malignancy. A 35-year-old female patient presented with a larger rash/erythema on the head and neck and felt itchy.

DIAGNOSES

A large erythema/rash and white, sterile pustules based on erythema spread from head, neck to the whole body in a short period of time. Blood cell results showed high levels of white blood cell, neutrophils, C-reactive protein and interleukin-10, and decreased levels of some immune indicators. Pathological biopsy results showed that there was immune cell infiltration around the superficial dermis.

INTERVENTIONS

Immediate avoidance of potential allergens and treatment with steroids, antihistamines and other medications, followed by adjustment with cyclosporine and human immunoglobulin.

OUTCOMES

At 1 year's follow-up, the patient did not develop any symptoms of discomfort and increased awareness of allergen prevention.

LESSONS

The reported case is an extremely rare and severe AGEP, typically characterized by pruritus, edema, large erythema/rash, dense white needle-like sterile pustules based on erythema/rash, and desquamation. After discontinuation of exposure to iodixanol, the patient received symptomatic supportive treatment, mainly drug response. She eventually recovered without recurrence. In the future, with the in-depth exploration of more studies, the use of Iodine Contrast Media will be more standardized and scientific.

Acute Generalized Exanthematous Pustulosis: Clinical Features, Differential Diagnosis, and Management

Acute generalized exanthematous pustulosis (AGEP) is a rare, acute, severe cutaneous adverse reaction mainly attributed to drugs, although other triggers, including infections, vaccinations, ingestion of various substances, and spider bites, have also been described. AGEP is characterized by the development of edema and erythema followed by the eruption of multiple punctate, non-follicular, sterile pustules and subsequent desquamation. AGEP typically has a rapid onset and prompt resolution within a few weeks. The differential diagnoses for AGEP are broad and include infectious, inflammatory, and drug-induced etiologies. Diagnosis of AGEP depends on both clinical and histologic criteria, as cases of overlap with other disease processes have been reported. Management includes removal of the offending drug or treatment of the underlying cause, if necessary, and supportive care, as AGEP is a self-limited disease. This review aims to provide an overview and update on the epidemiology, pathogenesis, reported precipitating factors, differentials, diagnosis, and management of AGEP.

Clinical features of acute generalized exanthematous pustulosis caused by hydroxychloroquine in rheumatology patients and exploration of CARD14 gene mutations

Introduction

Acute generalized exanthematous pustulosis (AGEP) is a rare condition characterized by superficial pustules following drug ingestion or infection. Currently, there is no clear link between rheumatism and AGEP. It has been described that hydroxychloroquine (HCQ) is a rare cause of acute generalized epidermal necrolysis (AGEP). Presently, there are limited studies on HCQ-induced AGEP. We aimed to explore the clinical features and associated gene expression of AGEP induced after HCQ treatment exposure in rheumatology patients.

Methods

We assessed patients with HCQ-induced AGEP diagnosed at the Second Affiliated Hospital of Guizhou University of Chinese Medicine between January 1, 2017, and May 1, 2022. We also reviewed similar cases reported in specific databases.

Results

The study included five females (mean age, 40.2 years), and the mean time from initiation of HCQ treatment to symptom onset was 12.2 d. All patients received steroids and allergy medications after HCQ discontinuation, and the rash completely resolved within an average of 25.2 d. We performed whole exome sequencing and Sanger validation in our patient sample. CARD14 gene mutations were detected in three patients. Additionally, seven mutation sites were detected.

Discussion

HCQ-induced AGEP may have a longer latency period and regression time than AGEP induced by other drugs. Our patients all experienced CARD14 gene mutations. AGEP often resolves with topical therapy and drug discontinuation, although some cases require systemic steroid therapy. In the future, patients with rheumatism should pay attention to the effectiveness of HCQ during treatment and be aware of the associated skin toxicity.

Results of patch testing in Acute generalized exanthematous pustulosis (AGEP): a literature review

The literature on positive patch test results in acute generalized exanthematous pustulosis (AGEP) is reviewed. 93 drugs were identified that have together caused 259 positive patch tests in 248 patients suffering from AGEP. The drug classes causing the highest number of reactions are beta-lactam antibiotics (25.9%), other antibiotics (20.8%), iodinated contrast media (7.3%) and corticosteroids (5.4%), together accounting for nearly 60% of all reactions. The highest number of reactions to individual drugs was to amoxicillin (n=36), followed by pristinamycin (n=25), diltiazem (n=14), amoxicillin-clavulanic acid (n=13), clindamycin (n=11) and iomeprol (n=8); 59 of the 93 drugs each caused a single case only. The "Top-10" drugs together caused over 50% of all reactions. The sensitivity of patch testing (percentage of positive reactions) in patients with AGEP is largely unknown, but may generally be around 50%, which also applies to pristinamycin. Patch testing in AGEP appears to be safe, although mild recurrence of AGEP skin symptoms or other rashes may occur occasionally. Clinical aspects of AGEP, including epidemiology, etiology and pathophysiology, clinical features, histology, treatment, and prognosis are briefly presented, as are diagnosing the disease and identifying the culprit drugs with patch tests, intradermal tests, in vitro tests, and challenge tests. This article is protected by copyright. All rights reserved.

Drug Triggers and Clinic of Acute Generalized Exanthematous Pustulosis (AGEP): A Literature Case Series of 297 Patients

Acute generalized exanthematous pustulosis (AGEP) is a rare skin reaction, commonly caused by drugs. Available evidence mostly relies on small studies or case reports. We collected published AGEP case reports and, subsequently, described the patient characteristics, suspect and concomitant drugs, time to onset, disease management, and clinical prognosis. This study included 297 AGEP patients (64.3% women) obtained from 250 published case reports or case series with individual patient data. AGEP affected patients of all ages, but the majority of patients (88.2%) were ≥25 years old. The most frequently reported suspect drugs were anti-infectives for systemic use (36.5%), particularly antibacterials for systemic use (31.0%), and especially beta-lactam antibacterials (18.3%) and macrolides (4.3%). Other frequent suspect drugs were antineoplastics (12.2%), and anti-inflammatory/anti-rheumatic products (5.2%) plus hydroxychloroquine (12.8%). Mean time to onset was 9.1 days (standard deviation SD 13.94). Some patients developed fever (64.3%) and systemic involvement (18.9%), and most patients (76.4%) received pharmacological treatment for AGEP. Seven patients died, although five of them were already critically ill prior to AGEP. In conclusion, antibiotics remain the most common suspected cause of AGEP. While case mortality rate may be up to 2.5%, disentangling the role of AGEP on the fatal outcome from the role of the preexisting health conditions remains challenging.