Pediatric Patch Testing at Mayo Clinic Between 2016 and 2020.

Background: Allergic contact dermatitis (ACD) is a common condition within the pediatric population. Patch testing is an important way to identify relevant allergens. Objective: To provide an update of the common contact allergens seen in children based on patch testing data at our institution from 2016 to 2020. Methods: We performed a retrospective analysis of patch test data from children aged 1-18 years from 2016 to 2020 at Mayo Clinic. Reaction rates were compared to the rates reported by the Pediatric Contact Dermatitis Registry (PCDR). Results: One hundred ninety-two children aged 1-18 were patch tested to various allergens. A total of 15,457 allergens were tested, with 291 positive tests. The top 5 allergens with highest positive reaction rates were hydroperoxides of linalool, hydroperoxides of limonene, methylisothiazolinone, nickel, and cobalt. Seven of the top 38 allergens with the highest reaction rates are not currently included in the Mayo Clinic Pediatric Patch Test Series, and 11 are not currently included in the Pediatric Baseline Series (as developed by the Pediatric Contact Dermatitis Workgroup). Conclusions: Patch testing is a useful tool to diagnose children with ACD. With new products and exposures, there is an opportunity to expand current pediatric patch testing series.

Linear IgA bullous dermatosis of childhood: Retrospective single-center cohort.

Linear IgA bullous dermatosis (LABD) is a rare autoimmune blistering disorder impacting children and adults. In this single-center retrospective chart review of pediatric patients with LABD at a large tertiary referral center, we report the unifying and unique clinical features of 10 pediatric patients. Patients typically presented with the "cluster of jewels" sign (n = 6; 60%), mucous membrane involvement (n = 5; 50%) and had a mean disease duration of 38 months; six patients (60%) required inpatient admission for management of their skin disease, including all five patients who had mucous membrane involvement. Our findings suggest that pediatric LABD may be a disease with high morbidity and may be associated with severe complications when mucous membranes are involved.

Adult-onset linear IgA bullous dermatosis: a retrospective single-center cohort study of 81 patients and literature review.

BACKGROUND: Linear IgA bullous dermatosis (LABD) is a rare autoimmune blistering disorder that may be drug-induced or paraneoplastic. We aim to characterize features of LABD and determine differentiating factors among idiopathic, drug-induced, or malignancy-associated diseases. METHODS: We conducted a single-center retrospective chart review of adult patients with linear IgA bullous dermatosis at a large tertiary referral center and a literature review of adult linear IgA bullous dermatosis. RESULTS: Eighty-one patients were included in the study. Ten patients (12.3%) had comorbid malignancy and nine (11.1%) had inflammatory bowel disease. Median disease duration was significantly shorter in both drug-induced (1.2 vs. 48.8 months; P < 0.001) and malignancy-associated (1.7 vs. 48.8 months; P < 0.001) LABD compared with idiopathic LABD. Recurrent episodes occurred significantly more often in idiopathic LABD compared to those with drug-induced (76.1 vs. 11.5%; P < 0.001) or malignancy-associated disease (76.1 vs. 33.3%; P = 0.019). Time to diagnosis was significantly shorter in the drug-induced (0.2 vs. 5.4 months; P < 0.001) and malignancy-associated groups (0.7 vs. 5.4 months; P = 0.049) compared with idiopathic; similarly, time to improvement was significantly shorter in both drug-induced (0.4 vs. 3.0 months; P < 0.001) and malignancy-associated disease (1.1 vs. 3.0 months; P = 0.016). Clinical morphology was indistinguishable between groups. Limitations included retrospective data collection, data from tertiary referral centers, and limited racial and ethnic diversity. CONCLUSION: Screening for underlying malignancy, as well as for a predisposing medication or possibly inflammatory bowel disease, may be advisable in patients with LABD, particularly when it is newly diagnosed.