Clears Heat and resolves toxicity - Pang Xie is classically used for toxic skin presentations such as scabies, irritant dermatitis, and inflamed external lesions.
Dissipates Blood stasis and reduces swelling - older use includes traumatic injury and localized swelling where a cold, salty animal drug is chosen to break stagnant accumulation.
Assists treatment of scalds and external burns - the crab is typically charred, powdered, or applied externally rather than used as an everyday internal medicinal food.
Secondary Actions
This is a niche external-use medicinal and should not be confused with ordinary dietary crab consumption.
The herb's clinical identity is tied more to charcoal, powder, and topical handling than to routine decoction use.
Classical References
Traditional herb references describe Pang Xie as salty and cold, entering the Liver and Stomach to clear heat, dispel stasis, reduce swelling, and resolve toxin.
The standard indications of scabies, scalds, traumatic injury, and dermatitis show that Pang Xie belongs to the practical external-medicine side of Chinese materia medica.
Traditional administration methods emphasize charring, powdering, pills, or topical application rather than everyday food use.
Modern Research
Active Compounds
Chitin and chitosan from crab shell - the best studied crab-derived biomaterial fractions
Calcium carbonate from shell matrix - a mineral component relevant to powders and wound biomaterials
Astaxanthin and other carotenoids - antioxidant pigments associated with crustacean shell material
Shell proteins and peptides - structural and bioactive fractions used in regenerative-material research
Studied Effects
A blue-crab chitosan and protein hydrogel enriched with carotenoids showed notable wound-healing effects in vivo, offering a modern analogue for Pang Xie's traditional external role in injured and inflamed tissue (PMID 32487393).
A review of chitosan-based functional materials described strong hemostatic, anti-inflammatory, and granulation-promoting effects in skin wound repair, which helps explain why crab-derived materials remain relevant to external healing applications (PMID 33681176).
A 2025 study on blue-crab biogenic carbonates showed that even aged crustacean shell material retained structural calcium carbonate and embedded astaxanthin, reinforcing the biomedical interest of crab-derived external materials rather than directly validating broad internal use of Pang Xie (PMID 41303966).