In the Field
Chitosan is the reason Celox, ChitoGauze, and ChitoSAM stop bleeding even when the body's own clotting system is not working right. The shellfish-allergy question comes up in every class, and the answer is not complicated once you understand what chitosan actually is: a sugar, not a protein. The allergen in shellfish is the protein, and modern processing removes it. But that is a conversation worth having with your team before you hand out kits, not during a call.
Common Mistake
Assuming chitosan products are unsafe for patients with shellfish allergies without understanding the chemistry involved.
Technical Detail
Chitosan is a linear polysaccharide (a complex sugar) produced by the partial deacetylation of chitin, the primary structural component of the exoskeletons of shrimp, crab, and other crustaceans. In medical applications, chitosan is processed and purified to remove residual shellfish proteins and produce a biocompatible, biodegradable hemostatic agent.
Mechanism of action. Unlike kaolin-based hemostatic agents that accelerate the body's clotting cascade, chitosan works independently of the body's coagulation system. When chitosan contacts blood, its positively charged molecules bind electrostatically to the negatively charged membranes of red blood cells, forming a gel-like mucoadhesive barrier. This barrier physically seals the wound and promotes localized clot formation without requiring functional clotting factors.
Clinical implications. Because chitosan does not depend on the clotting cascade, it works in patients on anticoagulants (warfarin, rivaroxaban, apixaban), patients with coagulopathy from trauma-induced consumption, and hypothermic patients whose clotting function is impaired. This makes chitosan-based products particularly valuable in prolonged field care and patients with known bleeding disorders.
Shellfish allergy considerations. The allergenic component of shellfish is protein (primarily tropomyosin). Chitosan is a polysaccharide, not a protein. Modern manufacturing processes remove residual shellfish protein to negligible levels. Products such as ChitoSAM are specifically marketed on the basis of this purification, noting that their chitosan content poses no meaningful allergen risk. In clinical practice, allergic reactions to chitosan-based hemostatic dressings are rare to nonexistent. Providers should still verify the specific product's labeling and, where operationally feasible, obtain patient allergy history before use.
Field-approved chitosan products. CoTCCC currently recognizes Celox Gauze, ChitoGauze, and ChitoSAM as field-approved chitosan-based hemostatic dressings. Each is supplied as a gauze roll or Z-folded strip for wound packing.
