title: Inmunohistochemical detection of mastocytes in tissue from patients with actinic prurigo.
abstract: BACKGROUND
  Actinic prurigo (AP) is a type of photodermatosis, the pathophysiology of which has not been determined. AP has been suggested to be a hypersensitivity reaction to the presence of eosinophils and the local production of IgE.
  
  
  METHODS
  Descriptive study, using paraffin blocks of tissue that have been diagnosed with AP from the Dermopathology department, Hospital General Dr. Manuel Gea González. In 66 blocks from 63 patients, eosinophils were identified by hematoxylin and eosin staining, and mastocytes were labeled by immunohistochemistry. Three random microphotographs (40x) were used, and cell counts were calculated as the mean count in the 3 microphotographs.
  
  
  RESULTS
  Forty cases (63.5%) were female, and 23 (36.5%) were male. The mean age was 26.49 ±14.09 years; regarding the evolution time of the disease, the average was 11.93 years ±11.39. In 38 of 63 cases (60%), the lip, skin, and conjunctiva were affected clinically. In 22 of 63 cases (34%), AP cheilitis was the sole manifestation, and in 4 of 63 cases (6%), there were lesions in the skin and conjunctiva. The mean eosinophil count was 9 per case, the average number of mastocytes/field was 28.48 (range 0 to 66) Kruskal-Wallis p=0.001.
  
  
  CONCLUSIONS
  There are elements in AP that mediate the reaction of hypersensitivity type IV b, necessitating the identification of triggering factors.
  
  
  BACKGROUND
  Actinic prurigo, eosinophil, hypersensitivity IV b, IgE, mastocytes.
authors.affiliation: Dr. Manuel Gea Gonzalez General Hospital, Dermatology, Mexico City.
authors.forename: Eduwiges
authors.initials: E
authors.lastname: Martínez-Luna
authors.affiliation: Oral Pathology, Juarez University of Durango State.
authors.forename: Ronell
authors.initials: R
authors.lastname: Bologna-Molina
authors.affiliation: Oral Pathology, University Autonoma Metropolitana, Mexico City.
authors.forename: Adalberto
authors.initials: A
authors.lastname: Mosqueda-Taylor
authors.affiliation: Oral Pathology, Juarez University of Durango State.
authors.forename: Juan-Carlos
authors.initials: JC
authors.lastname: Cuevas-González
authors.affiliation: Dr. Manuel Gea Gonzalez General Hospital, Dermatology, Mexico City.
authors.forename: Erika
authors.initials: E
authors.lastname: Rodríguez-Lobato
authors.affiliation: Dr. Manuel Gea Gonzalez General Hospital, Dermatology, Mexico City.
authors.forename: María-Abril
authors.initials: MA
authors.lastname: Martínez-Velasco
authors.affiliation: Dr. Manuel Gea Gonzalez General Hospital, Dermatology, Mexico City.
authors.forename: María-Elisa
authors.initials: ME
authors.lastname: Vega-Memíje