title: Patterns of skin prick test positivity in allergic patients: usefulness of a nationwide SPT chart review.
abstract: BACKGROUND
  A previous survey on allergens used by Mexican allergists in their skin prick test (SPT) panel showed wide variation. Humidity varies in different zones of Mexico. This might lead to differences in natural exposure and allergic sensitisation throughout the country. We aim to describe the SPT sensitivity patterns in the different climatic zones in Mexico and to show the usefulness of a structured SPT chart-review including multiple clinics in obtaining these allergen sensitisation patterns.
  
  
  METHODS
  A retrospective, structured chart-review of SPT results was undertaken in allergy clinics throughout Mexico. Ratios of SPT positivity were calculated for individual allergens, per climatic zone and nation-wide. Per allergen group the most important allergens were identified. Statistically significant differences between zones and the nation-wide data were tested with Pearson's Chi-squares test.
  
  
  RESULTS
  4169 skin test charts were recollected. The most important allergens causing sensitisation were very similar in different zones, despite climate variation. The allergen with highest ratio of SPT positivity was Dermatophagoides pteronyssinus (51%), with trees (Ash-27%, Alder-22%, Oak19%), and Bermuda grass (26%) as second and third. In the hot zones (humid and dry) Aspergillus was statistically significant more frequently than in more temperate zones. Cockroaches thrive in big cities and humid zones and Mesquite and Poplar in dry zones. Weeds are less important.
  
  
  CONCLUSIONS
  Mexico has its own SPT sensitisation pattern, which is different from America and Europe. A structured chart-review of SPT results is able to show this and might be a tool for allergists in other countries.
authors.affiliation: Hospital Médica Sur, Mexico City, Mexico. marlar1@prodigy.net.mx
authors.forename: D E
authors.initials: DE
authors.lastname: Larenas-Linnemann
authors.forename: G A Guidos
authors.initials: GA
authors.lastname: Fogelbach
authors.forename: A Monteverde
authors.initials: AM
authors.lastname: Alatorre
authors.forename: A Arias
authors.initials: AA
authors.lastname: Cruz
authors.forename: D D Hernández
authors.initials: DD
authors.lastname: Colín
authors.forename: J A Luna
authors.initials: JA
authors.lastname: Pech
authors.forename: A Medina
authors.initials: AM
authors.lastname: Hernández
authors.forename: D Alberto García
authors.initials: DA
authors.lastname: Imperial
authors.forename: M L Cid
authors.initials: ML
authors.lastname: del Prado
authors.forename: F J Linares
authors.initials: FJ
authors.lastname: Zapién
authors.forename: R E
authors.initials: RE
authors.lastname: Huerta
authors.forename: J A Ortega
authors.initials: JA
authors.lastname: Martell
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D039741:Antigens, Dermatophagoides / Q000009:adverse effects / Q000276:immunology; D052179:Antigens, Plant / Q000009:adverse effects / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D002980:Climate; D031744:Cynodon; D005260:Female; D006306:Health Surveys; D006801:Humans; D006967:Hypersensitivity / Q000175:diagnosis* / Q000453:epidemiology* / Q000276:immunology; D008297:Male; D008800:Mexico; D008875:Middle Aged; D039981:Pyroglyphidae; D012189:Retrospective Studies; D012882:Skin Tests; D014197:Trees
chemical_list: D039741:Antigens, Dermatophagoides; D052179:Antigens, Plant