Gelatins


Gelatins are used as plasma expanders in emergency situations. Fluid gelatins are produced by hydrolysis of collagen and chemical modification:
  • succinylation (modified fluid gelatin);
     
  • cross-linking with glyoxal and subsequent degradation by oxidation and heating (oxypolygelatin);
     
  • cross-linking with hexamethylene diisocyanate (urea linked gelatin).

Incidence
Gelatins linked to urea: 0.146% to 0.852% administrations (0.048% of serious manifestations).

Oxypolygelatins: 0.617% of administrations.

Modified fluid gelatins: 0.066% to 0.338 % of administrations (0.016% of serious manifestations).
 

Risk factors
Gelatin allergy (gummy bears, sweets/foods such as liquorice, marshmallows, corned beef, brawn, fruit yogurt, instant whipped cream, instant pudding, juices).

Drug allergy.

Male gender.
 

Clinical manifestations
General: anaphylactic shock
Cutaneous: urticaria +++.
Respiratory: bronchospasm.
ENT: sneezing.

Classification of allergic reactions:

I urticaria, flush
 

II same + nausea +dyspnea + tachycardia, arterial hypotension
 

III same + vomiting, diarrhea + bronchospasm + cyanosis + shock
 

IV same + respiratory arrest + cardiac arrest
 

V death

Diagnostic methods
Cutaneous testing
 
Intradermal skin-tests: positive from 1/1000 to 1/10 in a few patients with anaphylactic shock
 
Specific IgE (ImmunoCAP/Pharmacia CAP System).
 
Histamine-release by blood basophils.
 
Mechanisms
Direct histamine-release (urea linked gelatins by excess of diisocyanate)
 
IgE-mediated hypersensitivity.
 
Management
Antihistamines H1 and H2 are useful in prevention of minor cutaneous reactions.
 
Avoidance of gelatins.

References

  1. Laxenaire M.C, Charpentier C, Feldman L, "Réactions anaphylactoïdes aux substituts colloidaux du plasma: incidence, facteur de risque, mécanismes. Enquête prospective multicentrique française", Ann.Fr.Anesth.Reanim., 1994 ; 13 (3): 301-10
  2. Duffy B.L, Harding J.N, Fuller W.R, Peake S.L, "Cardiac arrest following Haemaccel", Anaesth. Intensive. Care., 1994 ; 22 (1): 90-2
  3. Ring J, "Anaphylactoid reactions to intravenous solutions used for volume substitution", Clin. Rev. Allergy, 1991 ; 9(3-4): 397-414.
  4. Wahl R, Kleinhans D, "IgE-mediated allergic reactions to fruit gums and investigation of cross-reactivity between gelatin and modified gelatin-containing products", Clin. Exp. Allergy., 1989 ; 19 (1): 77-80
  5. Vervloet D, Senft M, Dugue P, Arnaud A, Charpin J, "Anaphylactic reactions to modified fluid gelatins", J. Allergy. Clin. Immunol, 1983 ; 71: 535-40

As in all diagnostic testing, the diagnosis is made by the physican based on both test results and the patient history.