Study design, setting and participants
Children aged 2 to 17 who had admitted to the Pediatric Allergy and
Asthma Unit of Gulhane School of Medicine with reactions after mosquito
bites between 2015 and 2018 were enrolled in the study along with age
and sex-matched control subjects who tolerated several mosquito bites
without any unusual or large local reaction. Children in the control
group had no history of physician-diagnosed allergic diseases and they
admitted to our outpatient department for routine medical checkup.
Mosquito allergy was defined as large local reactions to mosquito bites
consist of itchy, red, warm swellings appearing within minutes of the
bites, and atypical reactions such as itchy papules, ecchymotic,
vesiculated, blistering, bullous reactions, appearing in 6 hours after
the bites and persisting for days or weeks (5). Demographic data,
history of mosquito allergy (onset of the reaction, reaction type) and
personal and familial history of other atopic diseases were recorded.
Physical examination, morphology and other clinical manifestations of
skin lesions were recorded. The skin reaction features of the children
at the time of enrollment were classified into five stages due to the
lifetime course of the process of sensitization and desensitization, as
previously reported: stage 1, the bites cause no or little reaction
(wheal < 4 mm, erythema < 4 mm or papule <
3 mm); stage 2, delayed reaction only (erythematous papules of
> 4 mm develop 3–4 h after bite and with a peak at 24–36
h); stage 3, immediate reaction followed by delayed reaction (wheal of
> 4 mm develops a peak ≤ 20 min after bite); stage 4,
immediate reaction only; and stage 5, those with repeated bites
eventually lose the reactions (2).
Asthma was defined as current symptoms (wheeze and cough) and positive
bronchodilator responsiveness (improvement of FEV1 by
12% or more following administration of 200 mcg salbutamol), and/or a
positive response to a trial of therapy with inhaled or oral
corticosteroids (6). Allergic rhinitis was defined by the presence of
rhinitis symptoms (rhinorrhea, nasal obstruction, nasal itching and
sneezing), which are reversible spontaneously or with treatment in
children with aeroallergen sensitization in the skin-prick test (7).
Atopic dermatitis was defined as the presence of pruritus and a
relapsing eczematous rash typically found over flexor surfaces (8).
The study was approved by the institutional review board of Gulhane
School of Medicine and written informed consent was obtained from
parents.
Study measurements