Food protein-induced enterocolitis syndrome – a review of the literature with focus on clinical management

Food protein-induced enterocolitis syndrome (FPIES) is a potentially severe presentation of non-IgE-mediated gastrointestinal food allergy (non-IgE-GI-FA) with heterogeneous clinical manifestations. Acute FPIES is typically characterized by profuse vomiting and lethargy, occurring classically 1-4 hours after ingestion of the offending food. When continuously exposed to the incriminated food, a chronic form has been described with persistent vomiting, diarrhea, and/or failure to thrive. Although affecting mainly infants, FPIES has also been described in adults. Although FPIES is actually one of the most actively studied non-IgE-GI-FAs, epidemiologic data are lacking, and estimation of the prevalence is based on a limited number of prospective studies. The exact pathomechanisms of FPIES remain not well defined, but recent data suggest involvement of neutrophils and mast cells, in addition to T cells. There is a wide range of food allergens that can cause FPIES with some geographical variations. The most frequently incriminated foods are cow milk, soy, and grains in Europe and USA. Furthermore, FPIES can be induced by foods usually considered as hypoallergenic, such as chicken, potatoes or rice. The diagnosis relies currently on typical clinical manifestations, resolving after the elimination of the offending food from the infant's/child's diet and/or an oral food challenge (OFC). The prognosis is usually favorable, with the vast majority of the case resolving before 5 years of age. Usually, assessment of tolerance acquisition by OFC is proposed every 12-18 months. Of note, a switch to an IgE-mediated FA is possible and has been suggested to be associated with a more severe phenotype. Avoiding the offending food requires education of the family of the affected child. A multidisciplinary approach including ideally allergists, gastroenterologists, dieticians, specialized nurses, and caregivers is often useful to optimize the management of these patients, that might be difficult

Specific Aspects of Drug Hypersensitivity in Children

Suspicion for drug hypersensitivity (DH) is a common reason for children's referral to an allergy department, with β-lactam antibiotics and nonsteroidal anti-inflammatory drugs (NSAIDs) as the most frequently involved drugs. The prevalence of DH in children remains not well defined as epidemiologic studies in children are lacking, and the most of those take into account adverse drug reactions (ADR) without a systematic allergy work-up to confirm or exclude hypersensitivity. The clinical history is mandatory in order to classify the reaction as being immediate or non-immediate and then to subsequently adapt the allergy work-up. Mainly due to the lack of studies, the same guidelines used for diagnosis of drug allergy in adults are generally used in the pediatric population, and the diagnosis is based mainly on in vivo tests (i.e. skin tests and/or drug provocation test) and rarely on in vitro tests. However, specific aspects of management of DH in children have been recently highlighted

Antibiotic allergies in children and adults: from clinical symptoms to skin testing diagnosis

Hypersensitivity reactions to β-lactam and non-β-lactam antibiotics are commonly reported. They can be classified as immediate or nonimmediate according to the time interval between the last drug administration and their onset. Immediate reactions occur within 1 hour after the last drug administration and are manifested clinically by urticaria and/or angioedema, rhinitis, bronchospasm, and anaphylactic shock; they may be mediated by specific IgE-antibodies. Nonimmediate reactions occur more than 1 hour after the last drug administration. The most common manifestations are maculopapular exanthems; specific T lymphocytes may be involved in this type of manifestation. The diagnostic evaluation of hypersensitivity reactions to antibiotics is usually complex. The patient's history is fundamental; the allergic examination is based mainly on in vivo tests selected on the basis of the clinical features and the type of reaction, immediate or nonimmediate. Immediate reactions can be assessed by immediate-reading skin tests and, in selected cases, drug provocation tests. Nonimmediate reactions can be assessed by delayed-reading skin tests, patch tests, and drug provocation tests. However, skin tests have been well validated mainly for β-lactams but less for other classes of antibiotics

Oral challenge without skin tests in children with non-severe beta-lactam hypersensitivity: Time to change the paradigm?

Suspected allergy to penicillins and cephalosporins is very common in childhood. After a proper evaluation, allergy will be confirmed only in a small portion of them. Intradermal tests are usually part of the allergy workup, but they are painful for children and time-consuming, and their role has been debated. A systematic review found only two studies reporting a positive predictive value of skin tests in children of 36% and 33%, respectively, leading to a high rate of inaccurate diagnosis. Moreover, considering that skin tests are negative in more than 90%-95% of cases, an oral provocation test (OPT) is finally needed to confirm tolerance in most of these children. Positive OPT are rare, and even where children demonstrate reproducible signs on challenge, they rarely constitute immediate or serious symptoms. Therefore, OPT to the index antibiotic without skin tests are increasingly being considered an accepted procedure for children with a suspected mild non-immediate reaction related to a beta-lactam antibiotic. Furthermore, a recent research has taken the same approach including children with suspected mild immediate reactions, with similar safety and positive results. In light of recent evidence highlighted, it is now the time for large and multicentric studies to confirm that OPT with the index antibiotic, without skin tests, are safe and convenient for children with a history of a mild reaction with a beta-lactam antibiotic before it can be recommended in pediatric allergy guidelines

Role of in vivo and in vitro Tests in the Diagnosis of Severe Cutaneous Adverse Reactions (SCAR) to Drug

Severe cutaneous adverse reactions (SCAR) are life-threatening conditions including acute generalized exanthematous pustulosis (AGEP), Stevens-Johnson Syndrome (SJS), toxic epidermal necrolysis (TEN) and drug reaction with eosinophilia and systemic symptoms (DRESS). Diagnosis of causative underlying drug hypersensitivity (DH) is mandatory due to the high morbidity and mortality upon re-exposure with the incriminated drug. If an underlying DH is suspected, in vivo test, including patch tests (PTs), delayed-reading intradermal tests (IDTs) and in vitro tests can be performed in selected patients for which the suspected culprit drug is mandatory, or in order to find a safe alternative treatment. Positivity of in vivo and in vitro tests in SCAR to drug varies depending on the type of reaction and the incriminated drugs. Due to the severe nature of these reactions, drug provocation test (DPT) is highly contraindicated in patients who experienced SCAR. Thus, sensitivity is based on positive test results in patients with a suggestive clinical history. Patch tests still remain the first-line diagnostic tests in the majority of patients with SCAR, followed, in case of negative results, by delayed-reading IDTs, with the exception of patients with bullous diseases where IDTs are still contra-indicated. In vitro tests have shown promising results in the diagnosis of SCAR to drug. Positivity is particularly high when the lymphocyte transformation test (LTT) is combined with cytokines and cytotoxic markers measurement (cyto-LTT), but this still has to be confirmed with larger studies. Due to the rarity of SCAR, large multi-center collaborative studies are needed to better study the sensitivity and specificity of in vivo and in vitro tests

Vaccine allergy

Overdiagnosis of vaccine allergy is considered a major public health problem. This article discusses the different types of allergic reactions after immunization based on the timing (immediate vs nonimmediate) and the extent of the reaction (local vs systemic). The vaccine components potentially responsible for an allergic reaction are discussed, as well as the management of patients with a history of reaction to a specific vaccine and those with a history of allergy to one of the vaccine components