IV. MAIN TEXT
To the Editor,
Nowadays food allergy represents an important public health problem both
in children and in adults, with an increasing prevalence in the last
years 1, 2. The worldwide epidemiology depends on
diagnostic methods, dietary habits and cultural practices2. The most common foods involved in children are
cow’s milk, egg, peanut, tree nut and wheat flour 1,
2. It is well known that adverse reactions commonly occur after
ingestion of food, with a wide range of clinical manifestations, such as
respiratory, cardiovascular, cutaneous and gastrointestinal symptoms,
and anaphylaxis 3. In literature adverse reactions
after inhalation of food particles are also described in highly
sensitive patients 3, so it is important to identify
and to follow-up them.
Here we describe the case of S., a 4-year-old female child followed up
by the Pediatric Allergology Unit of Messina University Hospital for
severe atopic dermatitis, allergic rhinitis, severe IgE-mediated
multi-food allergy (milk, egg, peanut, nut, legumes, kiwi) and suspected
transient hypogammaglobulinemia of infancy. Family history of allergic
rhinitis asthma and food allergy. Her parents are dairy owners. S.
didn’t take milk since she was five months old because of a failure to
thrive, vomiting, bloody diarrhoea and skin rashes after cow’s milk
consumption. At the beginning of our follow-up at the age of 2 years
old, Skin Prick Tests (SPT), Prick by Prick (PbP), Component Resolved
Diagnosis (CRD) and cow’s milk Challenge were performed. SPT were
positive for alpha-lactalbumin, beta-lactoglobulin and casein, with PbP
positivity for milk. CRD showed high specific IgE levels for Bos
d_milk, Bos d 4, Bos d 5, Bos d 8, Cap h_milk and Ovi a_milk
(Table 1 ). During the cow’s milk Challenge the baby developed a
severe anaphylaxis, characterized by urticaria, wheezing and loss of
consciousness, after the ingestion of 0,2 ml of milk. Intramuscular
injection of adrenaline and intravenous infusion of methylprednisolone
were administered, with the complete resolution of the symptoms in three
hours. Self-injectable adrenaline and strict avoidance of exposure to
cow’s milk proteins were prescripted. After some months, S. developed an
adverse reaction following the administration of nasal drops containing
lactoferrin, characterized by mild angioedema of the face and sneezing
attacks. At the age of 3 years old a new adverse reaction occurred in a
very unusual circumstance: the mother reported that the baby was playing
with her sister inside the parents’ dairy farm where she inhaled the
milk vapors released by the sheep milk making process. She immediately
developed anaphylaxis characterized by hives, angioedema of the face and
wheezing; the symptoms regressed after the oral administration of
antihistamines and oral corticosteroids.
The real epidemiology of allergic reactions induced by the inhalation of
food vapors and/or particles in children is still unknown3, 4. There are few data about its frequency in
current scientific literature. Roberts et al. reported that 5% of
children followed up for food allergy and asthma have respiratory
symptoms after inhaling food particles 5. The
inhalation of food allergens depends on its presence in the air: farms
or food industries, restaurants, school or home have been described as
the places where the reaction can most frequently occur4. In particular, processing of food, such as boiling,
may release a significant quantity of particles in the air. All of the
foods may induce clinical symptoms when inhaled, but the most commonly
reported in children are wheat flour, seafood, soy, legumes, peanut,
tree nut and cow’s milk 4. According to the clinical
case reported in this manuscript, Leonardi et al. wrote that allergic
reactions to airborne milk proteins have been described in literature,
in particular in children and adolescents with cow’s milk allergy during
the administration of inhaled drugs containing milk proteins3. Barbi et al. described the case of an 8-year-old
girl with asthma and cow’s milk allergy who developed a fatal
anaphylaxis while she was in a dairy shop 6.
Nowak-Wegrzyn et al. reported a case of anaphylaxis in an eight-year-old
boy with cow’s milk allergy and persistent asthma occurred after the
administration of Fluticasone/Salmeterol contaminated by lactose7. The diagnostic workup in these subjects is complex
and it is based on the history and the clinical evaluation of the
patient 3. The most frequent clinical manifestations
include respiratory symptoms (asthma, wheezing, coughing, sneezing
attacks and rhinitis), skin reactions (rashes or urticaria), ocular
symptoms (conjunctival hyperemia and lacrimation) and rarely anaphylaxis3, 4. It is important to establish the relationship
between the inhalation of the foods and the onset of the symptoms. Skin
testing (SPT and PbP) or serum-specific IgE for the foods suspected are
also important for the diagnosis 3, but nowadays CRD,
also known as Precision Allergy Molecular Diagnostic Applications
(PAMD@), have an increasing role in improving the management of allergic
diseases, in particular food allergy, because it may stratify the risk
of anaphylaxis during the Challenge 3, 8. However the
gold standard actually used to confirm the diagnosis of food allergy is
the Oral Challenge, with the ingestion of the suspected food by the
patient 3. There is no evidence in literature about
the use of specific inhalation Challenge in the field of food allergy,
although it is considered the reference for the diagnosis of
Occupational Rhinitis and Occupational Asthma; however its use is
limited in specialized centers 9. Being asthmatic is
the main risk factor in these patients. When an allergic patient has
experienced an adverse reaction after inhalation of food particles, the
dietary and environmental avoidance of the offending food has an
essential role 9, 10, as well as the educational
interventions on children and their families and the use of emergency
treatment in case of exposure to the allergen, represented by
intramuscular administration of Adrenaline, Short-Acting Beta Agonists
(SABAs), oral corticosteroids and antihistamines.
Our case report highlights the risk of anaphylaxis caused by inhalation
of milk vapors in children with severe food allergy. It is an event
rarely described and only adverse reactions related to cow’s milk vapors
are reported in current literature, hence to date our case represents
the first report describing an adverse reaction caused by the inhalation
of sheep’s milk vapors. According to the severe clinical course and the
possible airways involvement it is essential to identify the subjects at
risk, to limit the exposure to aerosolized food with environmental
measures and to practice the allergen avoidance diet and the emergency
treatment when anaphylaxis occurs.