Anisakiasis is a zoonotic parasitic infection that occurs as a result of the ingestion of raw or uncooked seafood such as a sea eel, banded rudderfish, and cuttlefish. It occurs most frequently in Northeast Asia (Korea, China, and Japan) because of the popularity of raw seafood ingestion [
3]. However, a recent increase in the ingestion of raw seafood in Western countries has led to an increase in the number of cases of anisakiasis reported in these areas [
2].
Anisakiasis begins with the accidental human ingestion of thethird stage larvae of marine mammal parasitic nematodes belonging to the family
Anisakidae. Family members
Anisakis simplex and
Pseudoterranova decipiens have been associated with human infection [
2].
Anisakis simplex is the most common causative parasite in reports from Northwest Asia and is most commonly associated with gastric anisakiasis. On the other hand,
Pseudoterranova decipiens is more common in European countries and is more commonly associated with intestinal anisakiasis. Grossly,
Anisakis simplex is smaller, thinner, and more brightly colored than
Pseudoterranova decipiens [
2]. Our patient was infected with
Anisakis simplex. Usually, when Anisakis has been ingested, the third stage larvae invade the esophageal and gastric mucosa. Acute symptoms including nausea, vomiting, epigastric pain, and low grade fever typically begin 2–12 hours after the ingestion of the infected seafood. In our case, larvae invaded the patient's oral mucosa immediately after ingestion of the infected cuttlefish, based on the onset of severe oral pain within 30 minutes. Chronic symptoms of anisakiasi sare dyspepsia, diarrhea, and epigastric pain lasting several weeks or months. Anaphylactoid reactions to larval secretions have been rarely reported [
2]. Because of the vague nature of the symptoms, the differential diagnosis also includes food poisoning, acute gastritis, acute gastric ulcer, cancer, and other parasite infections. That is, severe pain occurred when sperm bags of a squid were stuck to the oral cavity after the ingestion of raw squid [
4]. An eosinophilic leukocytosis is commonly found with laboratory testing; however, our patient's laboratory results were normal. We suspect that this was because the infection was in a very acute phase. In patients with chronic anisakiasis such as intestinal anisakiasis, anti-anisakis IgG/IgA antibody titers are available [
2]. But, first and foremost, obtaining a careful history regarding the ingestion of raw seafood is pivotal for establishing a diagnosis of anisakiasis [
1,
2,
3].
Gastroscopic or surgical removal of the larvae provides definitive diagnosis and treatment at the same time. For direct visualization of the larvae in the gastric or esophagus mucosa, EGD should be used. Generally, the invading larvae will degenerate without developing into adult worms; however, this can lead to granuloma formation [
5]. Therefore, complete removal of the larvae is the treatment of choice in patients with an acute infection. The most direct method for removal is extraction of the larvae. If the larvae cannot be extracted because they are too deeply embedded in the mucosa, resection including the larvae and the mucosa is an alternative treatment.
Regarding prevention, public education about the risks of raw seafood ingestion is most important. The Food and Drug Administration recommends in United States that raw foods be blast frozen to ≤ −35℃ for 15 hours, be normally frozen to ≤ −20℃ for 7 days, or be heated to ≥ 70℃, since larvae often survive at temperatures as high as 50℃ [
6]. Early evisceration of caught seafood can be recommended for preventing to migrate from the digestive tract of the captured organism to the muscle for several days. However, early evisceration may not be adequate to prevent all cases of anisakiasis because evisceration may not be performed completely. Also, in some fish infection of muscle is more prominent [
7]. Discouraging the ingestion of raw seafood can also decrease the incidence of anisakiasis.
Oral anisakiasis is a rare presentation of the parasitic infection anisakiasis. Severe oral pain can occur with one hour after the ingestion of raw seafood. With the aid of microscopic field, this disease can be detected and treated by a plastic surgeon.