Clinicopathologic Review: Synchronous White Lesions of the Lateral Tongue and Cheek
CORRECT ANSWER:
D. CONTACT REACTION
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DISCUSSION
The clinical appearance and distribution of the whitish lesions
of the buccal mucosa and lateral tongue in this case should
lead the clinician to consider the possibility of a contact
reaction to candy. One common allergen is cinnamic
aldehyde (or cinnamaldehyde), a compound found in
cinnamon and also used as a flavoring agent in many food
and candy products. Upon inquiry, our patient confirmed
daily use of cinnamon-flavored candy. Cinnamon aldehyde
mucositis can vary in its presentation and may mimic other
diseases of the oral cavity, such as a premalignant (dysplastic)
leukoplakia, oral hairy leukoplakia, or lichen planus. A cinnamon
reaction, or reaction to other types of contact allergens,
should be included on the differential diagnosis for multiple
diffuse leukoplakia in the oral cavity when the pattern of
distribution matches expected areas of contact with a candy,
food or oral hygiene product. 8, 10 Reactions to cinnamon gum
or candies often present as oblong, keratotic, shaggy white
patches in the areas of greatest contact with the allergen,
typically the lateral border of the tongue and the center of
the buccal mucosa. The lesions may be unilateral or bilateral,
depending on the habit. Rarely, cinnamon flavoring contact
reactions present as recurrent ulcers with a pattern resembling
erythema multiforme. Not infrequently, the reaction exhibits
a lichenoid pattern, as described in the next section. 5, 6 When
the flavoring agent is present in toothpastes, the condition
can present as a diffuse edema and erythema of the gingiva,
similar to that seen in plasma cell gingivitis. 1 It should be
noted that contact reactions are sometimes associated with a
burning sensation. Although not reported in our case, the
presence of burning would be a helpful diagnostic clue. 2, 5 Lichen planus
Lichen planus (LP) is a chronic inflammatory condition that
often presents as multiple, lacy, white lesions of the buccal
mucosa and other intraoral sites. 1, 8 Purple, pruritic, polygonal
papules of the skin may also be present. In our case, the
bilateral white lesions of the buccal mucosa could be
misinterpreted as the Wickham’s striae of LP. Lesions of the
lateral tongue are also seen in LP, and the distribution of the
lesions in this case could be misleading. However, careful
examination of the lesions in this case fails to reveal the
presence of true striations. It is important to note that, as
mentioned previously, a contact reaction to artificial
cinnamon flavoring could exhibit a lichen planus-like pattern.
Such lesions receive a diagnosis of lichenoid mucositis (LM).
A clinical and histologic mimicker of intraoral LP, LM is a type
IV (cell-mediated) hypersensitivity reaction that can develop
in reaction to a systemic drug or contact with an allergen,
such as cinnamon-flavoring, amalgam, oral hygiene products,
or other. 8 LM occurring in the context of a reaction to a
systemic drug would present diffusely, whereas a contact
reaction specifically affects the tissue(s) that is/are in direct
contact with the allergen. Erosions are also frequently seen
with LM. A biopsy is generally useful to help distinguish LP
from LM, unless clear evidence of a contact reaction is
observed or can be established. If the pattern is focal and
suspicious for a contact reaction, an attempt should be made
to identify a contact allergen before resorting to a biopsy.
Discontinuation of the suspected allergen should lead to
resolution of the leukoplakic lesion(s) in LM. 2, 8 As mentioned
above, a diagnosis of LP or LM would not be warranted in our
case, given the lack of lichenoid striations.
It is important for the clinician to be aware of the clinical
presentation of oral contact reactions in order to ask the right
questions and avoid an unnecessary biopsy. The patient
should be instructed to stop using the irritant for a minimum
of two weeks, and the area should then be re-evaluated.
Lesions that resolve following discontinuation are likely due
to a contact allergy. If the lesions persist, a biopsy may be
indicated to rule out dysplasia or another condition. Oral hairy leukoplakia
Oral hairy leukoplakia (OHL) should be a diagnostic
consideration in this case, given the presence of shaggy,
white, corrugated lesions of the lateral tongue. First described
in HIV-infected individuals, OHL is a manifestation of Epstein-
Barr Virus infection that usually affects immunocompromised
patients, including persons treated with steroids or other
immunosuppressant medications. 1, 4 While the condition has
also been reported in immunocompetent individuals, it is rare
in healthy, non-immunosuppressed patients. 7 Typically, OHL
presents as asymptomatic, bilateral, vertically-ridged, white
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