Pectin anaphylaxis and possible association with cashew allergy.
BACKGROUND
Inhalation of pectin has been identified as a cause of occupational asthma. However, allergic reactions to orally ingested pectin have not been reported.


OBJECTIVE
To describe a child with pectin-induced food anaphylaxis and to discuss its possible relationship to cashew allergy.


METHODS
A 3 1/2-year-old boy developed anaphylaxis once after eating cashews and later after eating a pectin-containing fruit "smoothie." He also has a history of generalized pruritus after eating grapefruit. Skin tests or radioallergosorbent tests (RASTs) were performed to pectin and other suspected food allergens.


RESULTS
The child had a positive skin prick test reaction to pectin and a high RAST reaction to cashew and pistachio. He had a low-level positive RAST reaction to grapefruit. Results of allergy tests for the other potential food allergens were negative. The pectin in the smoothie was confirmed to be of citrus origin. Review of previous case reports of pectin-induced occupational asthma revealed several patients with allergies to and cross-reactivity with cashew.


CONCLUSIONS
Ingestion, not only inhalation, of pectin can cause hypersensitivity reactions. Cashew, and possibly pistachio, allergy may be associated with pectin allergy, and the possibility of pectin allergy should be considered in cashew- or pistachio-allergic patients who have unexplained allergic reactions.
Ferdman
Ronald M
RM
Division of Clinical Immunology and Allergy, Childrens Hospital Los Angeles, Department of Pediatrics, Keck School of Medicine, University of Southern California, Los Angeles, California 90027, USA. rferdman@chla.usc.edu
Ong
Peck Y
PY
Church
Joseph A
JA
D031021:Anacardium / Q000009:adverse effects*; D000707:Anaphylaxis / Q000209:etiology* / Q000276:immunology; D002675:Child, Preschool; D002957:Citrus; D006801:Humans; D008297:Male; D021184:Nut Hypersensitivity; D010368:Pectins / Q000009:adverse effects*; D011852:Radioallergosorbent Test; D012882:Skin Tests
D010368:Pectins