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Incomplete auriculotemporal nerve syndrome – mimicry of oral allergy syndrome

European Journal of Dermatology. Volume 17, Number 2, 157-9, March-April 2007, Clinical report

DOI : 10.1684/ejd.2007.0131

Summary

Author(s) : Sybille Thoma-Uszynski, Vera Mahler , Department of Dermatology, University Hospital, Friedrich-Alexander-University, Erlangen-Nürnberg, Hartmannstrasse 14, D-91052 Erlangen, Germany.

Summary : Pollen allergies are commonly symptomatic as seasonal rhinoconjunctivitis. The majority of patients with pollen allergies develop an oral allergy syndrome due to cross-reactive homologous allergens in plant foods. Symptoms may vary from minor local oropharyngeal sensations and swelling to life threatening angioedema and glottis edema. We present the case of a 6-year-old male with suspected oral allergy syndrome who was referred for allergological work up. However, an incomplete auriculotemporal nerve syndrome was diagnosed, mimicking oral allergy syndrome.

Keywords : pollen food allergy syndrome (oral allergy syndrome), auriculotemporal nerve syndrome, facial erythema

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ARTICLE

Auteur(s) : Sybille Thoma-Uszynski, Vera Mahler

Department of Dermatology, University Hospital, Friedrich-Alexander-University, Erlangen-Nürnberg, Hartmannstrasse 14, D-91052 Erlangen, Germany

accepté le 10 Octobre 2006

Oral allergy syndrome (OAS) summarizes allergic reactions to food allergens with coexisting allergies to aeroallergens [1]. These allergies are based on cross-reactive homologous allergens present in related and unrelated plant species [2]. Commonly, patients suffer from seasonal rhinoconjunctivitis and oropharyngeal itching or burning. Typically, symptoms start a few minutes after intake of uncooked plant foods.

Case report

An 6-year-old male presented with a 2-year history of recurrent episodes of unilateral swelling and erythema on his right cheek shortly after intake of distinct fresh plant foods such as pears, apples, kiwis or carrots. Symptoms lasted only for a short period of time and disappeared spontaneously. At the same time he had developed seasonal rhinoconjunctivits.

The past medical history was unremarkable except for parotidectomy and lymphadenectomy after recurrent right-sided parotitis two years earlier.

On first presentation, the patient was asymptomatic. The prick tests to inhalant allergen sources and plant foods revealed positive wheal reactions of 4-6 mm and over 6 mm diameter to pollen allergens including grass, rye, birch, hazel, alder and red beech and 2-3 mm wheal reactions to anise, hazelnut, and caraway. The suspected plant foods pear, apple, kiwi and carrot were negative in the prick to prick test.

Provocation testing was performed. Open provocation with a tender pear did not provoke symptoms. However, chewing of a firm carrot revealed erythema at the right cheek (figure 1). Mucosal symptoms were absent. The iodine starch test as indicator of gustatory sweating was negative.

The differential diagnosis of unilateral facial erythema and swelling (i.e. Quincke’s edema, hereditary angioedema, acute contact dermatitis, erysipelas, N. flammeus [3]) could be ruled out clinically. In the context of the patient’s status post right-sided parotidectomy and provocation of symptoms by intense chewing of firm foods, the unilateral erythema without mucosal symptoms was diagnosed as incomplete auriculotemporal nerve syndrome.

Discussion

Incomplete auriculotemporal nerve syndrome is an infrequent disease which can be misdiagnosed as oral allergy syndrome. Understanding of OAS is based on recent insight into the molecular properties of allergens and cross reactivities of homologous pollen and food allergens [2, 4-8]. Based on botanical and molecular relationships, marker allergens could be defined [7]. Members of the PR 10 subfamily of pathogenesis related proteins, including the major birch pollen allergen Bet v 1 and homologous allergens from carrot, apple and pear [1, 6-8] could theoretically have been the relevant cross-reactive allergens in the case presented. However, in contrast to positive skin prick testing to tree pollen, including birch, hazel, alder (relevant for the patient’s seasonal rhinoconjunctivitis) all the suspected plant foods (pear, apple, kiwi and carrot) were negative and the patient did not develop mucosal symptoms upon oral provocation. Further differential diagnosis of unilateral facial erythema and swelling could be excluded.

The auriculotemporal syndrome (syn. Frey’s syndrome) was first described in the middle of the 18^th century by Duphenix [9] and later named after the neurologist Lucia Frey [10]. It represents a local hyperhidrosis in the innervation area of the N. auriculotemporalis after gustatory stimuli. It follows injury or surgery in the regio parotideomasseterica, neck dissection or luxation of the temporo-mandibular joint, parotitis or parotid abscess. It may also be a rare manifestation of diabetic neuropathy or post-herpetic neuralgia and may be a sign of Horner’s syndrome, which includes ipsilateral anhidrosis, ptosis, miosis and enophthalmus.

The onset of Frey’s syndrome occurs typically 1 month to 5 years post surgery or injury in the preauricular region and affects 37 to 100% of patients with such conditions [11]. In our case, the clinical manifestation was first observed two years after parotidectomy.

The pathophysiology of this syndrome is not precisely elucidated. It most frequently results from an injury to the auriculotemporal nerve. In addition, an irritation of the N. auriculotemporalis by scar formation had been suggested. Under normal conditions, the auriculotemporal nerve carries sensory fibers from the skin, parasympathetic fibers to the salivary glands and sympathetic fibers to the sweat glands of the preauricular region (figure 2A). According to the misdirection hypothesis of the pathogenesis of auriculotemporal nerve syndrome, parasympathetic nerve fibers regenerate aberrantly into the sweat glands as well as blood vessels of the skin of the preauricular region (figure 2B). In case of concomitant damage to the greater auricular nerve the infraauricular region (figure 2C) is also affected. The gustatory sweating in Frey’s syndrome is usually mild and is not necessarily induced by gustatory stimuli. Incomplete clinical variants of Frey’s syndrome, as demonstrated in our case, may present without sweating, but erythema, as a result of aberrant parasympathetic nerve fibers being predominantly redirected to cutaneous blood vessels.

Similar to our case, in the only previously reported case, a 21-year-old woman complained of erythema, sweating and heat in the right cheek after intake of several foods such as chocolate, fruits and nuts. Her history revealed a jaw fracture 2 years earlier [12].

Due to the mild symptoms only about 10% of patients require treatment to reduce gustatory sweating [11, 13]. The therapeutic options of the auriculotemporal nerve syndrome include topical application of aluminium chloride hexahydrate 20% solution, intracutanous injection of botulinum toxin A or oral intake of sage extract [14]. In the case presented no treatment and no elimination diet (previously recommended under the suspicion of OAS) was required.

Acknowledgements

Financial support: none. Conflict of interest: none.

References

1 Sloane D, Sheffer A. Oral allergy syndrome. Allergy Asthma Proc 2001; 22: 321-5.

2 Pauli G. Evolution in the understanding of cross-reactivities of respiratory allergens: the role of recombinant allergens. Int Arch Allergy Immunol 2000; 123: 183-95.

3 Mahler V, Kiesewetter F, Hornstein OP. Unilateral eyelid swelling in naevus flammeus faciei. Problems in differential diagnosis of unilateral eyelid swelling. Hautarzt 1994; 45: 792-8.

4 Kazemi-Shirazi L, Pauli G, Purohit A, et al. Quantitative IgE inhibition experiments with purified recombinant allergens indicate pollen-derived allergens as the sensitizing agents responsible for many forms of plant food allergy. J Allergy Clin Immunol 2000; 105: 116-25.

5 Breiteneder H, Mills EN. Molecular properties of food allergens. J Allergy Clin Immunol 2005; 115: 14-23.

6 Breiteneder H, Ebner C. Molecular and biochemical classification of plant-derived food allergens. J Allergy Clin Immunol 2000; 106: 27-36.

7 Mothes N, Horak F, Valenta R. Transition from a botanical to a molecular classification in tree pollen allergy: implications for diagnosis and therapy. Int Arch Allergy Immunol 2004; 135: 357-73.

8 Ballmer-Weber BK, Wangorsch A, Bohle B, et al. Component-resolved in vitro diagnosis in carrot allergy: Does the use of recombinant carrot allergens improve the reliability of the diagnostic procedure? Clin Exp Allergy 2005; 35: 970-8.

9 Duphenix, M. Observations sur les fistules du canal salivaire de Stenon I. Sur une playe complicquee a la joue ou le canal salivaire fut dechire. Memoires de l’Academie Royale de Chirurgie 1757; 3: 431-439.

10 Frey L. Le syndrome du nerve auriculotemporale. Rev Neurol 1923; 2: 97-104.

11 Sato K. Disorders of the eccrine sweat gland. In: Freeberg IM, Eisen AZ, Wolff K, Austen KF, Goldsmith LA, Katz SI, eds. Fitzpatrick’s Dermatology in General Medicine, 2003; (6th edition).

12 Sanchez-Morillas L, Reano MM, Rodriguez MM, et al. Auriculotemporal nerve syndrome. Allergol Immunopathol (Mad) 2003; 31: 288-90.

13 Bremerich A, Eufinger H, Rustemeyer J, et al. Mund Kiefer Gesichtschir 2001; 5: 33-6; [Frey syndrome].

14 Togel B, Greve B, Raulin C. Current therapeutic strategies for hyperhidrosis: a review. Eur J Dermatol 2002; 12: 219-23.