Thank you for your recent inquiry.
There are still questions in the case that you described. First, in the absence of any visual confirmation, we are still are unsure as to whether or not the lesions described are urticarial in nature. I agree that it would be extremely unusual for chronic urticaria to manifest itself only on the face and the dorsum of the hands. Therefore the diagnosis itself remains in question.
Nonetheless, since you posed the question with the assumption that the lesions are urticarial in nature, I will do my best to answer your question with this in mind.
As you are well aware, there is scant evidence to support a role of food allergy in the production of chronic urticaria. Over a decadse ago, diets were used to manage patients with this condition. Probably the most common was the "lamb-rice diet"(Journal of Human Nutrition and Dietetics
Volume 8, Issue 3, pages 159–166, June 199, Clinical & Experimental Allergy,Volume 25, Issue Supplement s1, pages 34–42, July 1995). However, probably because of lack of efficacy, such diets have lost favor, and are rarely used today. In my personal experience, I have not found diets to be helpful in this regard and therefore do not employ them. In addition, it is extremely difficult to judge the efficacy of any therapy in chronic idiopathic urticaria because of the natural "ebb and flow" of the illness and the difficulty in quantitating the severity of symptoms.
Nonetheless, I have copied for you below several abstracts of articles which do discuss protocols that might be applied should you wish to proceed with an elimination diet. The key principle of all of these diets is that an elimination period is followed by sequential oral challenges. Usually an elimination diet is carried out for a couple of weeks, and then individual food challenges are done approximately every third day.
As noted, I personally am not an advocate of this approach, and when I have tried it have found it extremely difficult to come to any conclusion as to a cause and effect relationship between the ingestion of foods and flares in the urticaria.
However, as noted, the abstracts below should give you more detail regarding carrying out protocols for food elimination diets followed by challenges should you wish to pursue this area further.
Thank you again for your inquiry and we hope this response is helpful to you.
Clin Exp Allergy. 2009 Jan;39(1):116-26.
Incremental build-up food challenge--a new diagnostic approach to evaluate pseudoallergic reactions in chronic urticaria: a pilot study: stepwise food challenge in chronic urticaria.
Bunselmeyer B, Laubach HJ, Schiller M, Stanke M, Luger TA, Brehler R.
Department of Dermatology, University Hospital Münster, Münster, Germany. Britta.Bunselmeyer@ukmuenster.de
Background: The remission rate of patients with chronic urticaria (CU) due to elimination diets varies between 31% and 71%. However, the diagnostic value of subsequent traditional oral provocation tests with food additives in capsules remains unsatisfactory.
Objectives: A newly incremental build-up food challenge (IBUF) for patients with CU was designed and implemented in an open pilot study. Primary endpoint was the percentage of patients developing urticaria during at least one step of IBUF after an initial complete remission due to a pseudoallergen-free elimination diet.
Methods: In total, 153 patients with CU were submitted for 5 weeks to a pseudoallergen-free diet. All patients with remission were included to the 6-week IBUF protocol, containing pseudoallergen-rich foods in a systematic and additive manner. The recurrence and severity of CU was evaluated by urticaria score. Subjective disturbance and quality of life were evaluated by patients' diary, visual analogue scale and quality of life questionnaire (CU-Q2oL). Subsequently, patients were followed up for 3-24 months after IBUF by a telephone interview.
Results: A total of 104 patients completed the pseudoallergen-free diet, whereby 51% reported partial, 17% complete and 32% no remission due to the diet. All diet responders showed a decrease in subjective impairment, urticaria and quality of life score (P<0.001 each). Eighty-six percent (12/14) of the patients reaching complete remission, showed a recurrence of urticaria symptoms during the IBUF protocol. Fifty-eight percent (7/12) of these patients still remained free of symptoms due to avoidance of IBUF-identified foods at telephone follow-up. In patients with partial remission to pseudoallergen-free diet, however, IBUF did not provide information about the cause of urticaria symptoms.
Conclusions: The newly developed IBUF protocol seemed to be a promising method for identifying individually incompatible foods in some CU patients. IBUF should be verified by randomized controlled trials to gain additional evidence for its diagnostic value.
Acta Derm Venereol. 1995 Nov;75(6):484-7.
Pseudoallergen-free diet in the treatment of chronic urticaria. A prospective study.
Zuberbier T, Chantraine-Hess S, Hartmann K, Czarnetzki BM.
Department of Dermatology, Virchow-Klinikum, Humboldt Universität-zu Berlin, Germany.
In chronic urticaria, the possible pathogenetic role of pseudoallergic reactions to food has been repeatedly discussed, but stringent prospective studies regarding their clinical significance are not available. All patients with chronic urticaria and/or angioedema hospitalized at the department of dermatology during a period of 2 years were therefore included in a prospective study. Patients (n = 64) were screened for common causes of urticaria and then evaluated for possible benefits of a stringently controlled pseudoallergen-free diet. Double-blind, placebo-controlled oral provocation tests with food additives were performed on those patients benefitting from diet. In 73% of patients, symptoms ceased or were greatly reduced within 2 weeks on diet, although only 19% of them responded to individual pseudoallergens on provocation tests. Of the remaining patients, 11% responded to treatment of an associated inflammatory disease, and in 16%, no cause of the urticaria was ascertained. Follow-up at 6 months after hospitalization showed complete remission on diet in 46% and lasting improvement in all but one of the remaining patients on diet. An additive-free, stringently controlled diet thus provides a simple means of diagnosing and treating the majority of patients with chronic urticaria.
Ann Allergy. 1984 Dec;53(6 Pt 2):678-82.
Management of food allergies.
The mainstay of successful management of food allergy is the identification of the offending food(s), as verified by the elimination-challenge test. Dietary elimination is the most effective and inexpensive method, but its success depends on several factors. Initially, dietary elimination may need to be strict, but later certain patients may discover that they can tolerate limited quantities or certain preparations of the offending food without significant symptoms. In certain cases, provision of a substitute or a nutritional supplement may be needed. Food allergy in infants who are exclusively breast-fed requires elimination of the offending food from the mother's diet. Because of cross-antigenicity, certain patients may also need to avoid other members of the food family. This phenomenon is especially noticeable among seafoods. In certain patients who have mild to moderate sensitivity to multiple foods that cannot be completely avoided, rotation diets may be both effective and more convenient. In a few patients, conventionalelimination diets may be followed for limited time periods until all offending foods are identified. In addition to symptomatic treatment, pharmacologic agents may be taken for prophylaxis. Antihistamines, oral cromolyn and possibly other medications, when taken before an anticipated exposure or on a regular basis, may prevent or minimize the symptoms in certain patients. At present, no adequate evidence supports the use of hyposensitization therapy with food extracts. The prognosis of food allergy is more favorable in children than in adults. Most food-sensitive infants and young children will tolerate the offending food after 1-2 years of avoidance.
Phil Lieberman, M.D.