Skin Testing and Drug Provocation Tests in Epidermal Necrolysis: A French Experience

BACKGROUND

There are limited data on the use of skin testing, other than patch testing, and challenges in the evaluation of epidermal necrolysis (EN), including Stevens-Johnson syndrome and toxic epidermal necrolysis.

OBJECTIVE

To report a French multicenter experience in skin testing and challenges in EN, and investigate the factors associated with tests' positivity.

METHODS

All patients who were evaluated by patch tests (PTs), skin prick tests, intradermal tests (IDTs), or drug provocation tests (DPTs) for EN between 2010 and 2020 were retrospectively included through 2 French drug reaction networks.

RESULTS

In total, 113 patients were included from 8 centers. Median (interquartile range) time from EN to hypersensitivity workup was 7.9 months (5.1-15 months). All patients had PTs, 17 (15%) had skin prick tests or IDTs with delayed readings and 32 (28.3%) had DPTs. One mild reaction occurred after a DPT. Overall, 22 patients (19.5%) had positive PTs, and the only factors associated with positivity were Algorithm of Drug Causality for Epidermal Necrolysis (ALDEN) score and drug class. Only 1 IDT was positive but considered irrelevant. The DPTs were never performed to prove responsibility of a highly suspected drug but were used to confirm current tolerance of needed medications.

CONCLUSIONS

Allergological workup in EN, performed by specialists involved in EN, seems safe. Skin tests, although of limited sensitivity, can be helpful for considering the reintroduction of essential drugs according to a benefit-to-risk decision. We propose an algorithm for approaching hypersensitivity testing in patients with EN, to be adapted to each patient.

Spectrum of anti tubercular therapy induced cutaneous adverse drug reactions and its management through rechallenge: A prospective study at a Tertiary Care Centre

INTRODUCTION

The use of multi-drug regimens including 1st and 2nd line anti tubercular drugs in management of tuberculosis (TB) has been associated with undesirable adverse drug reactions including cutaneous one. Re-challenge remains the only option to restart the safe therapy and combat the tuberculous infection simultaneously.

MATERIALS AND METHODOLOGY

This cross-sectional study was conducted via prospective review of outpatients as well as indoor patients who presented with cutaneous adverse drug reactions to ATT between March 2020 and March 2021. Data were analysed regarding demographic profile, site of TB, ATT regimen, pattern of cutaneous lesions, offending drugs, past history of drug allergy, and reinstitution of ATT after re-challenge.

RESULTS

Out of total 56 registered tubercular patients presented with cutaneous adverse drug reaction 30 were females (53.57%). The most common site of TB was pulmonary followed by cervical lymph node TB. The three most common adverse drug reaction detected were maculopapular rash 32 (57.1%) followed by lichenoid drug eruptions in 6 (10.7%) and urticaria in 2 (3.6%). Ethambutol was found to be common offending drug followed by other first line anti-tubercular drugs. 5 patients developed multiple drug hypersensitivity on re-challenging and have to introduce steroids along with ATT.

CONCLUSION

Adverse cutaneous drug reactions to ATT is like a double-edged sword as stopping ATT and starting treatment with systemic steroids can further flare up the infection with increased risk of disseminated and multidrug resistant tuberculosis. Re-challenge was found out to be safest way in identifying culprit drug and hence to restart a safer alternate ATT regimen for better management.

Deep Neural Network for Early Image Diagnosis of Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis

BACKGROUND

Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) is a life-threatening cutaneous adverse drug reaction (cADR). Distinguishing SJS/TEN from nonsevere cADRs is difficult, especially in the early stages of the disease.

OBJECTIVE

To overcome this limitation, we developed a computer-aided diagnosis system for the early diagnosis of SJS/TEN, powered by a deep convolutional neural network (DCNN).

METHODS

We trained a DCNN using a dataset of 26,661 individual lesion images obtained from 123 patients with a diagnosis of SJS/TEN or nonsevere cADRs. The DCNN's accuracy of classification was compared with that of 10 board-certified dermatologists and 24 trainee dermatologists.

RESULTS

The DCNN achieved 84.6% sensitivity (95% confidence interval [CI], 80.6-88.6), whereas the sensitivities of the board-certified dermatologists and trainee dermatologists were 31.3 % (95% CI, 20.9-41.8; P < .0001) and 27.8% (95% CI, 22.6-32.5; P < .0001), respectively. The negative predictive value was 94.6% (95% CI, 93.2-96.0) for the DCNN, 68.1% (95% CI, 66.1-70.0; P < .0001) for the board-certified dermatologists, and 67.4% (95% CI, 66.1-68.7; P < .0001) for the trainee dermatologists. The area under the receiver operating characteristic curve of the DCNN for a SJS/TEN diagnosis was 0.873, which was significantly higher than that for all board-certified dermatologists and trainee dermatologists.

CONCLUSIONS

We developed a DCNN to classify SJS/TEN and nonsevere cADRs based on individual lesion images of erythema. The DCNN performed significantly better than did dermatologists in classifying SJS/TEN from skin images.

DRESS and AGEP Reactions to Iodinated Contrast Media: A French Case Series

BACKGROUND

Drug reactions with eosinophilia and systemic symptoms (DRESSs) and acute generalized exanthematous pustulosis (AGEP) are potentially severe cutaneous adverse drug reactions.

OBJECTIVE

To describe the clinical findings and sensitization profiles of DRESS and AGEP patients who had been administered iodinated contrast media (ICM).

METHODS

All adult patients in the dermatologist's French Investigators for Skin Adverse Reactions to Drugs (FISARD) network diagnosed with a DRESS or AGEP highly suspected to have been caused by an ICM were included retrospectively.

RESULTS

Thirteen DRESS patients and 19 AGEP patients who had been administered ICM were included, and the median delay in DRESS and AGEP occurrence after ICM administration was short, 4 and 1 days, respectively. Five AGEP patients had systemic involvement. A high cosensitization rate (46%) was observed among the DRESS patients, mainly with beta-lactam antibiotics. Overall, 77% of our patients were sensitized to several ICM. Patch tests identified the suspected ICM for 21 cases (72%). The retrospective nature, the limited number of subjects, the absence of a control group of healthy individuals, and the lack of detailed information on previous exposure to sensitizing drugs are limitations of this study.

CONCLUSIONS

We report a large series of DRESSs and AGEPs related to ICM administration. Skin tests appear useful for diagnosis and potentially to identify alternative ICM.

Cutaneous adverse drug reactions to psychotropic drugs and their risk factors - a case-control study

Cutaneous adverse drug reactions (CADRs) in patients with psychotropic drugs are common. Large studies on the relevant drugs and other risk factors are still scarce. 594 cases of severe CADRs ("cases") were compared with 8085 cases of other adverse drug reactions ("non-cases") documented in a pharmacovigilance program in psychiatry (AMSP) from 1993 to 2014. Logistic regression was carried out to determine risk factors and between-drug differences. CADRs were relatively more prevalent in patients treated with clomipramine, maprotiline, carbamazepine, lamotrigine, acamprosate, clomethiazole and disulfiram as well as with antidepressants and anticonvulsants as drug classes (p < 0.01). For these drugs, significantly more women were found in patients using maprotiline, lamotrigine (not carbamazepine) and in the groups of antidepressants, tricyclics and anticonvulsants (p < 0.01). Women were more vulnerable to CADRs (67% in cases and 56% in non-cases, p < 0.01). The significantly higher rate of CADRs in women was mainly observed under age of 50 years, i.e. during female reproductive years. In a multivariate logistic regression, female sex, the diagnostic group ICD F1 (substance abuse), maprotiline, carbamazepine, lamotrigine and clomethiazole were identified as risk factors of CADRs. The case/non-case approach allowed to identify risk factors based on empirical data rather than experts' evaluations. The new findings of substance abuse and clomethiazole as risk factors for CADRs have to be confirmed in further studies. Since CADRs can be life-threatening, it is important to be aware of risk factors, especially women during their reproductive period and with lamotrigine treatment.

Stamping a Case of Cutaneous Adverse Drug Reaction: Proving Beyond Causality Assessment

Different types of skin testing with a suspected drug have been reported to be helpful in determining the cause of cutaneous adverse drug reactions (CADRs). It is of utmost importance for practicing dermatologists to have a first hand knowledge of different types of skin tests available in a case of CADR. In each suspected case, a detailed investigation with the suspected agent and correlation of the positive skin reaction with clinical variant of CADR is advocated. Drug skin tests are performed 6 weeks to 6 months after complete healing of the CADR. Drug patch tests are performed similar to the methods used in patch testing in studying contact dermatitis. The commercialized form of the drug used by the patient is tested at 30% dilution. The pure drug is tested at 10% dilution. In severe CADR, drug patch tests should be performed at lower concentrations. It is also of value to test on the most affected site of the initial CADR.

Incidence of adverse cutaneous drug reactions in 22,866 Chinese inpatients: a prospective study

Cutaneous adverse drug reactions (ADRs) are common. However, no prospective study assessing cutaneous ADRs is available for Chinese populations. This study aimed to assess the incidence, manifestations, causative drugs, and other factors related to cutaneous ADRs. A total of 22,866 inpatients were surveyed prospectively from January to April 2012 at the Peking Union Medical College Hospital. Only cutaneous ADRs induced by systemic drugs were considered. Fifty cases were confirmed as cutaneous ADRs, for an estimated incidence of 2.2 per 1000 during this period (95 % confidence interval 1.6-2.8). Cases of cutaneous ADRs comprised 69 % females, while 63 % of all inpatients were female (χ (2) = 0.641, P = 0.427). The department of infectious diseases was the most frequently involved department. Morbilliform exanthema (40 %) was the most frequent cutaneous ADR, followed by urticaria (23.1 %). Anti-infection drugs (36.9 %) caused most cases of cutaneous ADRs, followed by iodinated contrast media (ICM, 18.5 %) and non-steroidal anti-inflammatory drugs (NSAIDs, 18.5 %). The most frequently associated disorders were cancer (24 %), infection (22 %), cardiovascular and cerebrovascular diseases (20 %), and autoimmune diseases (18 %). In this first prospective study assessing the incidence of cutaneous ADRs in China, anti-infection drugs were the most commonly involved drugs, followed by ICM and NSAIDs. No evidence of increased cutaneous ADR incidence in AIDS or SLE patients was observed. Our findings indicate that cancer and its treatments were often related to cutaneous ADRs in China.

Tenofovir induced lichenoid drug eruption

Cutaneous adverse reactions are a common complication of anti-retroviral therapy. Tenofovir is a newer anti-retroviral drug belonging to the nucleotide reverse transcriptase inhibitor group. Systemic adverse effects like nausea, vomiting, diarrhea, hepatotoxicity and renal toxicity are common with tenofovir but cutaneous adverse effects are rare. Lichenoid drug eruptions are a common adverse effect seen with a large variety of drugs including antimalarials, antihypertensives, nonsteroidal anti-inflammatory drugs and diuretics. Lichenoid drug eruption is a rare cutaneous adverse effect of tenofovir with only a single case reported till date. Here, we report a case of tenofovir induced lichenoid drug eruption in a 54-year-old human immunodeficiency virus affected male who presented with generalized lichenoid eruption after 6 weeks of initiation of tenofovir and complete clearance on cessation of the drug.

Toxic epidermal necrolysis due to lamotrigine in a pediatric patient

A 12-year-male child developed toxic epidermal necrolysis (TEN) probably due to lamotrigine. The patient was on antiepileptic therapy (sodium valproate and clonazepam) since 6–7 months, and lamotrigine was added in the regimen 1–2 months back. A serious cutaneous reaction is more likely to occur during the first 2 months of starting lamotrigine. The use of lamotrigine as an add-on to valproate may have precipitated the reaction. Other drugs were ruled out based on the incubation period of TEN. Drug interactions should be kept in mind with multiple antiepileptic therapies. The patient died because of the severity of reactions and delay in starting the treatment with steroids. One must be vigilant in early detection of the reaction.