What is the Difference Between Pinworms and Threadworms

Generally, pinworms are the parasitic roundworms that cause enterobiasis, and threadworms and seatworms are other names for the same parasite. Therefore, there is no significant difference between pinworms and threadworms. Furthermore, pinworms are common types of intestinal parasite or helminth, especially in humans. Since the adult pinworms are thread-like, they are known as threadworms. Moreover, the adult pinworms are light-yellowish in color, and they are clearly, visually detectable during the night at the anus or on toilet paper.  

Pinworms lay individual eggs in the intestine. Their eggs can be visualized under the low-power of the microscope. Both adult pinworms and their eggs are the two main factors that help to diagnose their infection. 

Key Areas Covered 

1. Pinworms
     – Taxonomy, Characteristics, Infection
2. Threadworms
     – Significance
3. What is the Difference Between Pinworms and Threadworms

Key Terms 

Eggs, Intestine, Itching, Parasitic Roundworms, Pinworms, Seatworms, Threadworms 

Pinworms – Taxonomy, Characteristics, Infection 

Pinworms (Enterobius vermicularis) are parasitic roundworms that mainly infect the large intestine. Moreover, pinworm infection is more common in children. Generally, the form of infection caused by pinworms is enterobiasis. Furthermore, the root of the infection is from faeces to mouth. Also, the indirect method of infection is through contaminated food. Usually, pinworm eggs can survive outside for about three weeks. 

Difference Between Pinworms and Threadworms

Figure 1: Pinworm Lifecycle

Furthermore, pinworms live in the colon and the rectum. Inside the body, they attach to the wall of the intestine by their head. Moreover, they consume food in the intestine to grow new body segments. However, old body segments break off from the worm, and they contain eggs. These segments leave the body along with the faeces. At night, female worms come out to lay eggs on the skin around the anus. On the other hand, this produces symptoms of the pinworm infection, including the very itching bottom, disturbed sleep, discomfort, irritability due to itching, and evidence of worms in faeces.

Pinworms vs Threadworms

Figure 2: Pinworm Eggs

Moreover, the male pinworm is 2-5 mm long and 0.2 mm thick. However, the female pinworm is 8-13 mm long and 0.5 mm thick. Their eggs are 50 to 60 μm long and 20 to 30 μm wide. Besides, their eggs are colourless. However, females lay mostly individual eggs, which are thousands in number. Eggs are translucent, and therefore, they can attach to the surfaces. They also contain a fully-developed larva that grows to 140–150 μm in length or a developing embryo. Furthermore, their complete life cycle occurs inside the gastrointestinal tract from about 2-4 weeks or 4-8 weeks.  

Threadworms – Significance 

‘Threadworms’ is another name for pinworms given as their adult worms are thread-like. 

Difference Between Pinworms and Threadworms 

  • Threadworms is another name given to pinworms as their adult form is thread-like. 
  • Therefore, there is no significant difference between pinworms and threadworms.


Pinworms are a common type of parasitic roundworm. They cause a pinworm infection known as enterobiasis. Generally, pinworms lay individual eggs in the intestine, and they are observable under the light microscope. However, their adult worms are thread-like. Therefore, threadworms is another name for pinworms. Hence, there is no significant difference between pinworms and threadworms.   


1. “Worms: How To Tell If You Have Tapeworms or Pinworms.” WebMD, WebMD, Available Here.

Image Courtesy:

1. “Enterobius vermicularis life cycle” By SuSanA Secretariat (CC BY 2.0) via Commons Wikimedia   
2. “Enterobius vermicularis” By DPDx, PHIL (Public Domain) via Commons Wikimedia   

About the Author: Lakna

Lakna, a graduate in Molecular Biology and Biochemistry, is a Molecular Biologist and has a broad and keen interest in the discovery of nature related things. She has a keen interest in writing articles regarding science.

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