Diphyllobothriasis Clinical Presentation

Updated: Jun 10, 2021
  • Author: Shireen R Chacko, MBBS; Chief Editor: Pranatharthi Haran Chandrasekar, MBBS, MD  more...
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Most persons with diphyllobothriasis are asymptomatic. The vast majority of patients who are diagnosed present with passage of proglottids.

Among persons with diphyllobothriasis who are symptomatic, the following are the most common symptoms [30] :

  • Passage of proglottids
  • Indigestion or dyspepsia
  • Abdominal discomfort

Other, less common, symptoms include the following:

  • Fatigue
  • Diarrhea
  • Dizziness
  • Weakness (rare)
  • Numbness of extremities
  • Sensation of hunger
  • Pruritus ani

Gastrointestinal (GI) obstruction is rare, but when it does occur, it manifests as acute abdominal pain associated with vomiting, distention, or both. [19]

Megaloblastic anemia is also rare. Studies note that about 40% of patients have decreased serum vitamin B12 levels, but fewer than 2% of patients are anemic. [31, 1] Patients with an underlying problem (eg, celiac disease or congenital malabsorption) are at higher risk of developing a symptomatic infection. Anemic patients can present with pallor, breathlessness, and neurologic symptoms such as weakness, numbness, and disturbances in coordination. The symptoms depend on the severity.


Physical Examination

D latum has an unusual affinity for vitamin B12, and the presentation of diphyllobothriasis may resemble that of megaloblastic anemia. No typical examination findings are noted, except for those seen in severe cases of anemia. Because significant anemia affects less than 2% of persons infected with D latum, most patients with diphyllobothriasis have no signs of illness.

The following physical findings associated with diphyllobothriasis are rare and are most likely related to underlying nutritional anemia:

  • Pallor
  • Glossitis
  • Dyspnea
  • Tachycardia
  • Weakness
  • Hypoesthesia
  • Paresthesias
  • Disturbances of movement and coordination, loss of vibratory sense and proprioception (related to degeneration of the posterior columns of the spinal cord)

If the patient presents with obstruction, the following physical findings may be noted:

  • Abdominal tenderness
  • Abdominal distention
  • Peritoneal signs


Rarely, patients with diphyllobothriasis may need surgical relief for obstruction or replacement of vitamin B12 or iron.