Chiari malformations are a heterogeneous group of disorders that are defined by anatomical anomalies of the cerebellum, brainstem, and craniocervical junction. They present a downward displacement of the cerebellum either alone or together with the spinal cord¹. There are three main types: malformation of Chiari Type I (MC-I) is characterized by having abnormally shaped cerebellar tonsils that move below the level of the foramen magnum. Chiari II malformation (MC-II), also known as Arnold–Chiari malformation, is characterized by a downward displacement of both the vermis and the cerebellar tonsils, associated with malformation of the brainstem and myelomeningocele. The Chiari III Type malformation (MC-III) is the rarest of all, and it is characterized by cervical or occipital encephalocele with the displacement of the brainstem to the spinal canal and usually with sliding of the cerebellar tonsils². Fornix anomalies and other structures in the fetal brain are probably responsible for the abnormalities in cognitive function that is frequently observed in individuals with myelomeningocele. These abnormalities have important effects on brain development being the main cause of cognitive deficits, attention deficit, poor executive skills, stridor, and apnea, and they are also responsible for high mortality³. Latex allergy is a public health problem in patients with risk groups, and within these vulnerable groups, patients with congenital malformations such as myelomeningocele have the risk of anaphylactic reactions to latex during surgeries or radiological procedures⁴. It has been documented that performing surgeries before 3 months of age was significant as a risk factor for developing latex allergy in patients with spina bifida (p=0.008, RM=5.4, 95% confidence interval=0.7−29.2)⁵. The prevalence of latex allergy in children with spina bifida or with urogenital anomalies varies between 32.6% in studies using skin tests and 34-72% in those based on serological tests⁶. At least 13 latex allergens have been identified; Hev b1 and Hev b3 are the allergens most assiduously involved in the sensitization of children affected by congenital malformations, Hev b2 and Hev b4 are the most important in the case of health workers, Hev b5 is recognized by the immunoglobulin E (IgE) of both groups, and finally, Hev b6 more frequently sensitizes the workers in the rubber industry⁷. The clinical manifestations are diverse, they can be local or systemic, they consist of any combination of: angioedema, rhinitis, conjunctivitis, asthma and anaphylaxis. They depend on the route of exposure to latex, the amount of allergen and personal characteristics⁸. Cutaneous manifestations are the most frequent, one of which is acute urticaria, which is caused by an immediate-type hypersensitivity (Type I) to the components of the protein present in latex. Another form of presentation is contact dermatitis caused by a mechanism of delayed-type immune injury (Type IV), which is diagnosed by patch tests⁹. In addition to allergy to latex proteins, cross-reactions can occur with other allergens that cross-react with proteins contained in some fruits; about 30-50% of patients allergic to latex show symptoms of allergy to foods derived from plants, especially fruits called latex-fruit syndrome which manifests clinically from an oral allergy syndrome to anaphylactic shock¹⁰,¹¹. The fruits most commonly involved are banana, avocado, kiwi, papaya, passion fruit, melon, pineapple, peach, and chestnut. On the other hand, in patients with latex positive skin tests, 60% of these have the possibility of presenting latex-fruit syndrome and 100% of patients with a latex negative skin test can hardly present this syndrome. Latex can also be a dangerous allergen when it is hidden in other substances; some cases of postprandial anaphylaxis are attributed to contamination of food by the use of latex gloves in its preparation¹²-¹⁵. The clinical history is the most important diagnostic element, and it is essential to identify the risk categories to subject these patients to diagnostic tests. TIt is important to investigate in all patients with probable latex allergy, the presence of clinical manifestations caused by contact with latex objects (In children, peribucal angioedema occurs immediately after inflating balloons), it is also essential to evaluate unexplained episodes of urticaria or anaphylaxis¹⁶. Within the diagnostic tests, the intraepidermal (prick) tests are the diagnostic method for detection of Type I hypersensitivity which have a risk of minimal anaphylaxis with high sensitivity and specificity¹⁷, in vitro tests such as specific serum IgE (ImmunoCAP) quantification tests have greater discordance than tests cutaneous and vary between 23 and 83%, and other non-standardized tests that can be performed during the diagnostic protocol are those of provocation; however, they are reserved if the skin tests are negative¹⁸. In the case of latex-fruit syndrome, for the diagnosis of food allergens it is advisable to perform a variety of skin tests known as intraepidermal tests with fresh food (prick to prick), this technique is more consistent with evidence of food exposure than intraepidermal tests made with commercial extracts¹⁹. On the other hand, until today, the best therapeutic and economic option is the avoidance of latex, and the treatment of clinical manifestations with pharmacotherapy is possible but unfortunately not curative²⁰. The use of allergen-specific immunotherapy is controversial because it has variable efficacy and is limited by the frequency and severity of adverse reactions²¹. Finally, monoclonal antibody treatment is under investigation for use in patients with latex allergy, and only it has been prescribed in isolated cases under the indication "off label" combined with the use of specific immunotherapy with allergens²². The opportune diagnosis of latex allergy in patients of risk groups allows to implement the prevention measures of latex allergy; in this way, it is possible to reduce the risk of severe reactions, which will reduce both morbidity and mortality and, therefore, the costs of medical attention. We report the case of a patient with latex allergy and latex-fruit syndrome with a history of Arnold–Chiari malformation and lumbosacral myelomeningocele.

• ¹
  Disorders of segmentation of the neural tube:chiari malformations

  Handb Clin Neurol, 2008
  Disorders of segmentation of the neural tube:chiari malformations
• ²
  History, anatomic forms, and pathogenesis of chiari I malformations

  Childs Nerv Syst, 2004
  History, anatomic forms, and pathogenesis of chiari I malformations
• ³
  Arnold chiari, or "Cruveilhier cleland chiari" malformation

  J Neurol Neurosurg Psychiatry, 2000
  Arnold chiari, or "Cruveilhier cleland chiari" malformation
• ⁴
  Educational challenges of latex protein allergy

  Immunol Allergy Clin North Am, 1995
  4. Thompson RL. Educational challenges of latex protein allergy. Immunol Allergy Clin North Am. 1995;15:159-74.
• ⁵
  Risk factors for latex sensitization in children with spina bifida

  Allergol Immunopathol (Madr), 2002
  Risk factors for latex sensitization in children with spina bifida
• ⁶
  Prevalence of latex allergy in spina bifida:genetic and environmental risk factors

  Eur Rev Med Pharmacol Sci, 2007
  Prevalence of latex allergy in spina bifida:genetic and environmental risk factors
• ⁷
  Latex allergy

  Ann Allergy, 1993
  7. Slater JE. Latex allergy. Ann Allergy. 1993;70:1-2.
• ⁸
  Manifestaciones clínicas

  Alergia al Látex, 2002
  8. Blanco C, Almeida L. Manifestaciones clínicas. In:Blanco C, Quirse S, editors. Alergia al Látex. Barcelona:MRA Ediciones;2002. 42-62.
• ⁹
  Allergia al latice di gomma

  Anafilassi in Ambiente Ospedaliero, 1997
  9. BilóMB, Antonicelli L, Pucci S, Garritani MS, Farabollini B, Bonifazi F. Allergia al latice di gomma. In:Bonifazi F, Pietropaoli P, BilòMB, Antonicelli L, editors. Anafilassi in Ambiente Ospedaliero. Torino, Italia:Minerva Médica;1997. 18-33.
• ¹⁰
  Latex allergy:clinical features and cross-reactivity with fruits

  Ann Allergy, 1994
  Latex allergy:clinical features and cross-reactivity with fruits
• ¹¹
  Latex protein:a hidden "food" allergen?

  Allergy Asthma Proc, 2000
  Latex protein:a hidden "food" allergen?
• ¹²
  Guía Para los Pacientes Alérgicos al Látex,
  12. Guía Para los Pacientes Alérgicos al Látex. Available from:http://www.clinicasubiza.com/es-es/enfermedades/generales/alergiaall%C3%A1tex.aspx.
• ¹⁵
  The clinical implications of latex-fruit allergy

  Anaesthesia, 2008
  15. Laws P. The clinical implications of latex-fruit allergy. Anaesthesia. 2008;63:211-2.
• ¹⁶
  Alergia al látex

  Arch Argent Pediatr, 2006
  Alergia al látex
• ¹⁷
  Prevalence of latex sensitivity in children evaluated for inhalant allergy

  Allergy Proc, 1992
  Prevalence of latex sensitivity in children evaluated for inhalant allergy
• ¹⁸
  Clinical practice guidelines. Reducing the risk of anaphylaxis during anesthesia, abbreviated text

  Ann Fr Anesth Reanim, 2002
  Clinical practice guidelines. Reducing the risk of anaphylaxis during anesthesia, abbreviated text
• ¹⁹
  Identification of a Hevea brasiliensislatex manganese superoxide dismutase (Hev b 10) as a cross-reactive allergen

  Int Arch Allergy Immunol, 2001
  Identification of a Hevea brasiliensislatex manganese superoxide dismutase (Hev b 10) as a cross-reactive allergen
• ²⁰
  Latex as a significant source of Hevea brasiliensis allergen exposure

  Ann Allergy Asthma Immunol, 2009
  Latex as a significant source of Hevea brasiliensis allergen exposure
• ²¹
  Latex allergy:a model for therapy

  Clin Exp Allergy, 2008
  21. Rolland JM, O'Hehir RE. Latex allergy:a model for therapy. Clin Exp Allergy. 2008;38:898-912.
• ²²
  Anti-igE antibodies for the treatment of igE-mediated allergic diseases

  Adv Immunol, 2007
  Anti-igE antibodies for the treatment of igE-mediated allergic diseases

A 12-year-old male patient presented with no history of familial atopy, immunodeficiency, or autoimmunity. Pregnancy and birth: pregnancy number: 2, mom's age: 20 years old, pregnancy diagnosis month: 5th month, prenatal checkups: 5 consultation, use prescription drugs: vitamins and folic acid, prenatal diagnosis of open caudal myelodystrophy by ecografy. Was the birth cesarean at 38 weeks of gestation, Apgar score: 7/9, birth weight: 3,150 kg, birth length: 51 cm, omphalorrhexis: 10 day. Nutrition and feeding: breastfeeding: 3 months, ablation: 9 months. Feeding without problems or restrictions. Abnormal psychomotor development requires treatment with early stimulation for 4 years. Personal medical history: Chiari type II malformation, it was treated surgically in the postnatal period without presenting apparent complications, other surgical antecedents (Table 1). Infectious background has recurrent urinary tract infections since age 11 of age secondary to bladder lithiasis. Allergic background: at 6 years of age, he presented with Type B adverse reaction to diclofenac characterized by acute urticaria and dyspnea. The patient is not allergic to iodinated contrast media. His allergic disease began in 2009, the patient presented wheals located in his right arm, andioedema in his eyelids and pruritus, previously the patient had contact with a latex glove during blood test. For that reason he was taken to the emergency room where he was prescribed antihistamines. He has also presented angioedema on the lips to contact with balloons and pharyngeal pruritus with fruits such as mango and papaya. It is sent to our office for immunoallergic evaluation. Physical examination: awake and alert; oriented to person, place and time. Scissor gait. Rest of physical examination normal. Workup. Skin tests were done with prick technique, positive result to Latex and Quercus, confirming allergic etiology mediated by specific IgE. Prick to Prick tests, positive results to mango and papaya, confirming latex fruit syndrome. Finger test was normal, discarding mechanism of delayed-type immune injury. Blood studies: Immunological studies were performed. In conclusion, it is important to make a detailed clinical history and make diagnostic tests in order to identify patients at risk of latex allergy, and thereby avoid anaphylaxis during the procedure where latex is used (Figs. 1 and 2, Table 2).

Patients with Chiari malformations are notoriously the group with the highest prevalence of latex allergy, and these patients require repetitive surgeries or urine catheters, so they are at risk of developing a latex allergy. The main risk factors that have been described are the atopic background and the number of surgical interventions to which these patients have been subjected. Our case was a 12-year-old male patient with a history of Arnold–Chiari malformation who required at birth surgical management for the closure of myelomeningocele and placement of a peritoneal ventricular bypass valve with a change per month due to dysfunction of the same, adding three surgeries in the first 3 months of age, having a high risk of latex allergy coinciding with what is described in the literature. Latex allergy manifests itself acutely or chronically through immunological and non-immunological mechanisms. In our case, the patient presents with acute urticaria and facial angioedema due to the immunological mechanism of Type I IgE-dependent lesion. In addition to the allergy to latex proteins, cross-reactions with proteins contained in fruits may occur due to the highly allergenic composition, a condition known as latex-fruit syndrome. The diagnosis by clinical history is fundamental for the identification of patients in situations of risk, and the next step of the diagnostic algorithm is the realization of skin tests, followed by the determination of specific IgE and provocation tests; in our case, the diagnostic approach was initiated with the complete clinical history, and latex allergy was confirmed with standardized skin tests, being positive for latex and Quercus spp. considering a second diagnosis of pollen-fruit syndrome; the prick-to-prick tests for fruits were made for mango and papaya resulting positive. The finger test was negative, ruling out a type IV injury mechanism. Hev b1 and Hev b3 are the allergens with greater allergenicity in patients with spina bifida; however, the component diagnosis was not completed due to the high costs involved in its realization. In conclusion, it is important to identify patients with risk of latex allergy, through diagnostic resources available to avoid complications during procedures involving contact with latex such as anaphylactic shock.