Thank you for your inquiry.
I am in agreement with you in that I do not believe there is any validation that foods can be responsible for leukocytoclastic vasculitis in spite of the fact that lay websites and message boards claim a relationship between foods and this condition.
The literature is very sparse in this area, but there are at least two reports in the older literature claiming that foods can cause this condition. For completeness sake, I have copied below the abstracts of these two studies.
Nonetheless, again, I am in agreement with your reluctance to perform any further workup in this regard.
Thank you again for your inquiry and we hope this response is helpful to you.
Pediatr Allergy Immunol. 2002 Feb;13(1):68-71.
Severe food-induced vasculitis in two children.
Businco L, Falconieri P, Bellioni-Businco B, Bahna SL.
Allergy and Immunology Division, Department of Pediatrics, University of Rome, La Sapienza, Italy.
Food-induced vasculitis seems to be rare and is considered by some as controversial. The reported cases in the literature are few and mostly on adult patients. Described in this report are two children with severe vasculitis caused by specific foods. They were diagnosed at two separate allergy centers that have a special interest in food allergies. Case 1 was an 8-year-old girl with a 9-month history of cutaneous vasculitis with large joints involvement. Case 2 was a 23-month-old girl with an 8-month history of multiple hospitalizations for recurrent acute severe cutaneous and mucous membrane vasculitis with large joints involvement. In both patients, skin biopsy showed leucocytoclastic vasculitis. In neither of the patients could the symptoms be attributed to drug intake, infection, autoimmunity, or other systemic disease. Case 1 had a moderately elevated serum total immunoglobulin E (IgE) level and strongly positive skin test and radioallergosorbent test (RAST) to cow's milk and hen's egg, both of which were proven to be the cause by elimination-challenge tests. Case 2 had a slightly elevated serum total IgE level, but negative skin tests to foods, including chocolate that was suspected by the mother. Avoidance of chocolate resulted in remission, except following accidental ingestion of cocoa-containing products. These findings support the few previous reports on food-induced vasculitis, an entity that seems rare but may be more common than currently realized.
Hautarzt. 1988 May;39(5):318-21.
[Allergic vasculitis caused by food allergy].
[Article in German]
Eisenmann A, Ring J, von der Helm D, Meurer M, Braun-Falco O.
Dermatologische Klinik und Poliklinik, Ludwig-Maximilians-Universität München.
In two patients with leukocytoclastic vasculitis allergic reactions to foods were shown to be of clinical relevance. Intracutaneous tests with food allergens produced not only immediate wheal and flare reactions but also distinct inflammatory reactions after 8-24 h, which showed the histological and immunopathological characteristics of leukocytoclastic vasculitis. After controlled oral provocation with specific foods exacerbation of petechial lesions was observed. A striking improvement in the patients' condition was achieved by avoidance of the relevant foods and oral administration of cromoglycate.
Phil Lieberman, M.D.