Severity and threshold of peanut reactivity during hospital-based open oral food challenges: An international multicenter survey.

BACKGROUND: Peanut allergy is classically managed by food avoidance. Immunotherapy programs are available at some academic centers for selected patients reacting to small amounts of peanut during food challenge. We aimed to determine and compare reaction thresholds and prevalence of anaphylaxis during peanut oral challenges at multiple specialist allergy centers. METHODS: A retrospective, international survey of anonymized case records from seven specialist pediatric allergy centers from the UK and Ireland, as well as the Australian HealthNuts study. Demographic information, allergy test results, reaction severity and threshold during open oral peanut challenges were collated and analyzed. RESULTS: Of the 1634 children aged 1-18 years old included, 525 (32%) failed their peanut challenge. Twenty-eight percent reacted to 25 mg, while 38% only reacted after consuming 1 g or more of whole peanut. Anaphylaxis (55 [11%]) was 3 times more common in teenagers than younger children and the likelihood increased at all ages as children consuming more peanut at the challenge. Children who developed anaphylaxis to 25-200 mg of whole peanut were significantly older. Previous history of reaction did not predict reaction threshold or severity. CONCLUSIONS: More than a third of the children in this large international cohort tolerated the equivalent of one peanut in an oral challenge. Anaphylaxis, particularly to small amounts of peanut, was more common in older children. Tailored immunotherapy programs might be considered not only for children with low, but also higher reaction thresholds. Whether these programs could prevent heightened sensitivity and anaphylaxis to peanut with age also deserves further study.

Early Bilateral Gonadoblastoma in a Young Child with Mosaicism for Turner Syndrome and Trisomy 18 with Y Chromosome.

Mosaic Turner syndrome (TSM) commonly occurs in the form of 45,X/46,XX and 45,X/46,X,i(X)(q10). Mosaicism for a Y chromosome, 45,X/46,XY, has been well documented and is associated with increased risk of gonadoblastoma (GB). To date, there are only six reported cases of TSM with a trisomy 18 karyotype, and only two of these were phenotypically female with 45,X/47,XY,+18 karyotype. We present the case of a phenotypically female infant born with dysmorphic features. G-banded karyotype and interphase FISH of blood showed 45,X in 95% and 47,XY,+18 (trisomy 18) in 5% of cells analysed. However, interphase FISH of buccal cells showed only the presence of the 45,X cell line. Due to the presence of Y chromosome material, elective gonadectomy was performed at 13 months of age. There were bilateral streak ovaries with early evidence of GB bilaterally, a rudimentary uterus and bilateral fallopian tubes with unilateral ectopic adrenal tissue identified histologically. Interphase FISH of the gonadal tissue was similar to the blood findings with 45,X in 86% of cells and 47,XY,+18 in 14% of cells analysed. This case highlights a rare karyotype of TSM and trisomy 18 in the same patient and is the first reporting the associated finding of bilateral GB.