Possible allergic reaction to alginate used for dental impressions
Question:
Reviewed: February 24, 2020
9/21/2014
I have a question regarding possible allergic reaction to dental material. I have recently seen a dentist student with a history of diffuse urticaria following multiple dental impressions using alginae, which is seaweed derivative. About 5-6 hours after the procedure, she developed pruritic hives starting on her face and ears then spreading to her trunk and extremities. There were no other reactions. Antihistamines were helpful but multiple hospital visits were required on the first few days due to recurrent hives. On 2nd day, she had difficulty in breathing along with diffuse hives. However, the attending physician contributed her symptoms to hyperventilation. serum tryptase was 5 ng/mL. Her hives eventually resolved about 1 week later. Hives have not recurred since. Previous exposure to alginate was well tolerated (but to lesser extent). She denied shellfish or latex allergy. She also denied other alternative causes such as new drugs, foods or concurrent illness. Skin test to alginate was performed with negative result. However, she developed erythema surrounding skin test area (like flare?). Given the onset of her reaction, I have referred her to derm for patch test to alginate which is now awaiting.
I reviewed the literature and found only a little data on dental material allergy. It looks like allergic reaction is quite rare. Do you have any suggestion for the management of this patient?. She informed me that there is no alternative to alginate available and future exposure to alignate is possible. If she is really allergic to alginate, how should we manage her? Is prophylaxis antihistamine helpful?
Answer:
There are rare cases of purported allergy to the seaweed product, alginate. For your interest and that of our readers, I have copied below three such reports. Only one of these was substantiated by the demonstration of specific IgE to the alginate product.
I think you have done due diligence in your evaluation, and because we lack any standardized skin testing, and because I could not find any in vitro tests for specific IgE to alginate, I do not think there is anything else you can do in regards to the evaluation other than an oral challenge itself. But because of the rarity of reactions to alginate, and the fact that the reactions occurred five to six hours after the procedure, I would question the assertion that alginate is the culprit. Unfortunately, based upon your history, I have no other suggestions as to a cause. But in answer to your specific questions:
1. In direct contradiction to the statement of the dental student, there are quite a number of alginate substitutes available, and they are used widely throughout dental practices. They are available online and can be purchased quite easily. I have copied below the names of some of these products and the web link to the source of the alginate alternatives.
Of course, the easiest and safest thing to do is to simply use a non-alginate-containing dental impression material. The dental school may not normally use these substitutes, but this may be because of a matter of cost, not because they are not readily available. If they are reluctant to order it for that reason, then a conversation with the person in charge might convince them to order a supply for your patient. It seems to me that this might take care of the issue in the most expeditious way.
2. I cannot say whether an antihistamine would be helpful in preventing future reactions, but based upon the severity of the reactions as stated in your description, it would be doubtful that antihistamines would completely prevent recurrences.
So, in summary, I believe the preferred way of managing your patient is to use an alginate substitute. And as noted, such are readily available.
If this is impossible only because of restrictions at the university, I would suggest you personally contact the person in charge to see if you could obtain an exclusion for your patient, stating that continued exposures might cause a severe reaction. And certainly, when your student graduates and enters practice, she could order an alginate substitute for her personal use.
There is no "good alternative" to avoidance, and the only other suggested strategy would be to try an antihistamine.
Thank you again for your inquiry and we hope this response is helpful to you.
Int J Prosthodont. 2009 Jan-Feb;22(1):33-4.
Fatal anaphylactic shock due to a dental impression material.
Gangemi S1, Spagnolo EV, Cardia G, Minciullo PL.
1School of Allergy and Clinical Immunology, Department of Human Pathology, University of Messina, Messina, Italy.
Abstract
Materials used for dental impressions are usually safe. This study describes a case of fatal anaphylaxis that appeared immediately after the oral mucosa came into contact with an alginate paste used for dental impressions. The cadaveric examination and the postmortem toxicology report confirmed that the cause of death was anaphylactic shock. The patient was affected by both cardiovascular and lung diseases that worsened the condition and forbade the use of epinephrine. To the authors' knowledge, dental impression materials, and alginate in particular, have not been reported previously as being a cause of anaphylaxis.
Scott Med J. 1984 Apr; 29(2):90-5.
Pulmonary hypersensitivity in the alginate industry.
Henderson AK, Ranger AF, Lloyd J, McSharry C, Mills RJ, Moran F.
Abstract
Salts of alginic acid are complex polymerised polysaccharides which are chemically extracted from seaweed. Workers in the alginate industry are exposed to dust from dried milled seaweed and pure alginate compounds. In this survey of one of the two factories in Britain producing alginates, we found evidence of pulmonary hypersensitivity to seaweed dust in seven per cent of the total work force, and evidence of precipitating antibody to sodium alginate and seaweed extracts in the serum of 4.5 per cent of the work force. Challenge testing of a number of employees with symptoms showed a dual response with immediate airways obstruction, and a later loss of lung volume, with associated impairment of transfer factor.
Alginot
Stand By
Silgimix, Status Blue
IgE-mediated anaphylaxis to antacid, Allergy Volume 56, Issue 6, page 580, June 2001
Sincerely,
Phil Lieberman, M.D.