Allergic Contact Stomatitis
Arash Akhavan, Khalid Alghaithi, Morgan Rabach,
Nina Mirchandani, and Steven R. Cohen
A65-year-old women presented for evaluation of painful
mouth lesions 8 days after the repair of a dental bridge.
She had been instructed to apply a local anesthetic, Orabase
paste with benzocaine 20% (Colgate-Palmolive, New York,
NY), to the painful upper and lower gingivae for relief
of discomfort immediately following the dental procedure.
On the morning of the fifth day of applying Orabase
paste, painful blisters developed on the right side of the
mouth. A trial of oral prednisone (40 mg per day for 3 days)
was initiated by her internist; however, the painful uni-
lateral mouth blisters persisted. When she was referred to
one of the authors (S.R.C.), the physical examination re-
vealed blisters and erosions on the right buccal mucosa
(Fig 1) and right lingual mucosa (Fig 2). The lesions were
tender to palpation. No other signs or symptoms of disease
were identified. A suspected diagnosis of contact stomatitis
prompted the withdrawal of the topical anesthetic. The pain
subsided, and all erosions reepithelialized within 72 hours.
Subsequently, patch testing was carried out with a broad
range of chemicals, including chemical allergens of the
European Standard series; dental, preservative, medica-
ment, fragrance, and miscellaneous allergens (from Chemo-
technique Diagnostics, Malmo¨, Sweden); and commercial
Orabase Paste. Patch tests used Finn Chambers (Epitest Ltd
Oy, Tuusula, Finland) under occlusion for 48 hours. The
patches were removed and evaluated at 48 and 96 hours,
according to the following interpretation scheme: nega-
tive () or doubtful reaction (macular erythema of the
contact area), weak (+) reaction (erythema, edema, and
possible papules), strong (++) reaction (erythema, edema,
papules, and vesicles [< 50% of contact area]), and extreme
(+++) reaction (intense erythema and bullae or ulceration
[> 50% of contact area]). At the reading at 48 hours, there
was a + reaction to benzocaine 5% in petrolatum (pet) and
a ++ reaction to Orabase paste (Figs 3 and 4). At 96 hours,
strong reactions to both Orabase paste (+++) and benzo-
caine 5% pet (++) were evident. Positive reactions were
also seen at the sites of nickel sulfate (++) and bacitracin
(++). Allergic contact stomatitis from the benzocaine-
containing Orabase paste was considered the cause of the
painful oral blisters because the condition resolved when
use of the product was discontinued. The dental appliance
was never removed.
What Is Your Diagnosis?
From the Department of Dermatology, Mount Sinai School of Medicine,
New York, NY, and the Department of Medicine/Dermatology, Albert
Einstein College of Medicine, New York, NY.
Address reprint requests to Steven R. Cohen, MD, Department of Medicine/
Dermatology, Albert Einstein College of Medicine, 111 East 210th Street,
Bronx, NY 10467-2490. E-mail: firstname.lastname@example.org
Figure 1. Buccal and lingual mucosa with blisters.
RONALD R. BRANCACCIO, MD
7901 Fourth Ave.
Brooklyn, NY 11209-3957
Tel: 718-491-5800; Fax: 718-748-2151
LISA A. GARNER, MD
3310 A Broadway
Garland, TX 75043
Tel: 972-271-4141; Fax: 972-278-8691
Contact Puzzle features brief case reports that illustrate
dramatic and/or unusual examples of contact derma-
titis. Submitted manuscripts should be a maximum
of six pages printed in 12-point font, double spaced.
Format includes Case Report, Diagnosis, Discussion,
and References (six or less). A color photograph(s) of
the clinical problem is required; color photograph(s)
of patch-test results or ancillary test is optional.
Dermatitis, Vol 17, No 2 (June), 2006: pp 88–9088
Allergic contact stomatitis from benzocaine in Orabase
Despite being a well-recognized sensitizer, benzocaine
remains one of the most effective topical anesthetics for
painful disorders of the skin and mucous membranes. A
common medicament, benzocaine is formulated in nu-
merous over-the-counter oral products for pain relief
(Table 1). Allergic contact dermatitis from benzocaine is
well described in the literature.
and blisters of the mucosa are characteristic manifestations.
Positive patch-test reactions attributed to benzocaine in
North America from 1994 to 2000 range from 1.7 to 2.6%.
We describe a case of allergic contact stomatitis from
benzocaine in Orabase paste. Our patient presented with
unilateral mucosal pain associated with blisters that ap-
peared 5 days after she started using a commercial anes-
thetic paste containing benzocaine. Withdrawal of the
Figure 3. Benzocaine patch test showing a positive (+) result at
Figure 4. Patch test with Orabase paste, showing a positive (++)
result at 48 hours.
Figure 2. Allergic Contact Stomatitis.
Table 1. Commercially Available Oral Topical Medicaments Con-
3 in 1 Toothache Relief (C.S. Dent, Erlanger, KY)
Adult Oral Pain Relief, Topical Gel, 20% (Sheffield
Laboratories, New London, CT)
Anbesol Oral Gel/Liquid (Whitehall-Robbins Healthcare,
Babee Teething Lotion (Pfeiffer, Wilkes Barre, PA)
Baby Gumz (Lee Pharmaceuticals, South El Monte, CA)
Baby Orajel (Del Pharmaceuticals, Uniondale, NY)
Benzodent (Procter & Gamble, Cincinnati, OH)
Dentapaine Buccal Gel (Reese Pharmaceutical)
Dentemp’s Oral Pain Relief Topical Swab (Majestic Drug,
South Fallsburg, NY)
Dent’s Extra Strength Toothache (C.S. Dent)
Double-Action Toothache Kit (C.S. Dent)
Hurricaine (Beutlich, Waukegan, IL)
Little Teethers Oral Pain Relief Gel (Prestige Brands,
Numzident (Block Drugs, Jersey City, NJ)
Orabase, paste and gel (Colgate-Palmolive, New York, NY)
Orafix Medicated (GlaxoSmithKline Consumer, Research
Triangle Park, NC)
Orajel (Del Pharmaceuticals)
Orasept (Pharmakon Labs, Tampa, FL)
Orasol (Clay-Park Labs, Bronx, NY)
Oratect (MGI Pharma, Bloomington, MN)
Otrathol Oral Liquid (multiingredient) (GlaxoSmithKline
Red Cross Canker Sore Medication (Mentholatum, Scoresby,
Sensogard Gel/Solution (Block Drugs)
Tanac Lipstick/Liquid (Del Pharmaceuticals)
Teething Gel For Babies (Sheffield Laboratories)
Toothache Topical Liquid (Clay-Park Labs, Bronx, NY)
Toothache Gel (Roberts Pharmaceutical, Eaton, NJ)
Zilactin-B Oral Gel (Zila Pharmaceuticals, Phoenix, AZ)
Allergic Contact Stomatitis 89
product resulted in prompt resolution of disease symptoms
and signs. Patch testing revealed strong allergic reactions at
the sites of both benzocaine 5% pet and commercial
Orabase paste, which contained benzocaine 20% in a plas-
ticized hydrocarbon gel with cellulose gum, pectin, xanthan
gum, and unspecified flavorings and preservatives. Testing
with the components of Orabase paste (other than benzo-
caine) was not performed.
Notwithstanding the relatively low overall frequency
of benzocaine allergy
and the rare occurrence of oral sen-
sitivity to the agent, our case illustrates the importance of
maintaining a high index of suspicion for allergic con-
tact dermatitis and allergic contact stomatitis whenever
benzocaine-containing products are used to treat mucosal
or cutaneous pain.
To our knowledge, there has been only one previously
reported case of oral contact allergy to benzocaine.
instance, a 39-year-old man developed blisters and edema
of the oral mucosa after the application of a benzocaine gel.
Here we report, for the first time, a case of allergic contact
stomatitis from Orabase paste with benzocaine 20%.
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90 Akhavan et al