Skin testing might have a diagnostic role in immune complex-mediated hypersensitivity reactions.

Clinical applications of skin testing are known to help diagnose IgE-mediated and T-cell-mediated delayed cutaneous reactions. By contrast, drug-induced immune complex-mediated vasculitis is primarily diagnosed based on medical history, clinical setting and laboratory evidence of immune-complex formation, as there are no proven methods to identify the suspect culprit. We report three cases of drug- or biologic-induced immune complex-mediated vasculitis, in which the culprit agents could be confirmed by a positive intradermal test with later reading (between 12 and 24 h after the test), with verification by immunohistochemical or immunofluorescent results. The findings of our study suggest that skin tests with a delayed reading could have a potential role in diagnosing some instances of immune complex-mediated hypersensitivity reactions.

Key factors predicting the in-hospital mortality of patients with severe cutaneous adverse reactions in Thailand.

BACKGROUND: At present, no predictive models are available to determine the probability of in-hospital mortality rates (HMRs) in all phenotypes of severe cutaneous adverse reactions (SCARs). OBJECTIVES: Our study explored whether simple clinical and laboratory assessments could help predict the HMRs in any phenotypes of SCAR patients. METHODS: Factors influencing HMRs in 195 adults diagnosed with different SCAR phenotypes were identified, and their optimal cut-offs were determined by Youden's index. Predictive equations for HMRs for all SCAR patients and Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) patients were determined using the exact logistic regression models. RESULTS: Acute generalized exanthematous pustulosis (AGEP) patients were significantly older, with a short time from drug exposure to reaction, and higher neutrophil count compared to SJS/TEN and drug reaction with eosinophilia and systemic symptoms (DRESS, p < 0.001). Peripheral blood eosinophilia, atypical lymphocytosis and elevated liver transaminase enzymes were significantly higher in DRESS. SJS/TEN phenotype, age ≥ 71.5 years, neutrophil-to-lymphocyte ratio ≥ 4.08 (high NLR) and systemic infection were factors predicting in-hospital mortality in all SCAR subjects. The ALLSCAR model developed from these factors demonstrated high-diagnostic accuracy for predicting HMRs in all SCAR phenotypes (area under the receiver-operator curve (AUC) = 0.95). The risk of in-hospital death was significantly increased in SCAR patients with high NLR after adjusting for systemic infection. The model derived from high NLR, systemic infection and age yielded higher accuracy than SCORTEN (AUC = 0.77) for predicting the HMRs in SJS/TEN patients (AUC = 0.97). CONCLUSIONS: Being older, having systemic infection, having a high NLR and SJS/TEN phenotype increases ALLSCAR scores, which in turn increases the risk of in-hospital mortality. These basic clinical and laboratory parameters can easily be obtained in any hospital setting. Despite its simple approach, further validation of the model is warranted.

Skin manifestations and biophysical changes following weight reduction induced by bariatric surgery: A 2-year prospective study.

Skin manifestations and biophysical changes are observed in patients with morbid obesity. However, reports of changes after significant weight loss, particularly through post-bariatric surgery (BaS), are limited. The aim of this 2-year prospective study was to evaluate the prevalence of skin signs and their changes in patients with morbid obesity who underwent BaS. Thirty-one patients were recruited for the study, with a mean age of 38.35 (SD 10.61) years and a male preponderance (male = 19 [61.29%], female = 12 [38.71%]). Patients were scheduled for multiple visits at months 0, 3, 6, 12, 18, and 24 post-BaS. Each subject had a thorough skin examination, biophysical measurements, and laboratory tests at each visit. Striae, acanthosis nigricans (AN), and plantar hyperkeratosis were the most common skin findings (n = 30 [96.77%], 29 [93.55%], 29 [93.55%], respectively). BaS provided improvements in many skin manifestations, namely striae, AN, acrochordons, plantar hyperkeratosis, hirsutism, lymphedema, pruritus, acne, finger pebbles, and chronic venous insufficiency with varied cumulative rates of improvements. However, acute telogen effluvium was observed in 17 (54.84%) patients. Regarding skin biophysical properties, transepidermal water loss, skin hydration, and pH did not change, while sebum production on the face significantly decreased at months 3 and 6, and elasticity decreased at months 6 and 24. In conclusion, weight reduction by BaS provided improvements in various skin signs, although telogen effluvium was a common sequelae.

Delayed urticaria after BNT162b2 booster vaccination at previous intradermal test site with severe acute respiratory syndrome-coronavirus-2 spike protein.

Urticaria is a common cutaneous adverse event from coronavirus disease 2019 vaccination. Previous studies hypothesized that excipients as polyethylene glycol in BNT162b2 vaccine and polysorbate in ChAdOx1 nCoV-19 vaccine are allergens. A 28-year-old woman had urticaria after a booster vaccination with BNT162b2 at the site of previous intradermal injection with severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) spike protein. This reaction emphasized that delayed urticaria may not be an allergic reaction to excipient but rather to the immunogen as such as SARS-CoV-2 spike protein.