![page_1.jpg](https://images.hive.blog/DQmP57YGu9Soof2pRTxKB4GPM9rRqE7c7Grg4dFW4aMQGYW/page_1.jpg)



As a child even till now, I have always wanted to understand how a disease infects a person, medically, it is known as **pathogenesis** and so today I will be bringing to your knowledge not only ***pathogenesis of tinea pedis*** but fully detailed explanation of **tinea pedis**.

I will also be discussing on the dermatophyte related with **tinea pedis**(athlete foot). Dermatophyte is a group of fungi that affects the body surface, majorly places of the body where keratin is found.
Every pathogen require a comfortable habit to live in and dermatophytes are not exempted from doing the same. Dermatophytes always want an habitat where they can feed, find shelter and grow.





**THE SKIN -  AN HABITAT FOR DERMATOPHYTE**


![page_1.jpg](https://images.hive.blog/DQmdpqFpPwBDdK18e8tCHE4dDenNL9ni6r2PZhSwHzE2RWY/page_1.jpg)

 Dermatophytes attack the skin because it a comfortable habitat for them. They require keratin for growth and we are made to understand that keratin can be found on the skin, nails and hair.

>**The skin is the largest organ of the body. The uppermost layer of the epidermis of the skin called **stratum corneum** contains a pigment called **keratin** which is responsible for the toughness and flexibility of the skin. 
**Keratin** is a protein that helps form the hair,nails and the skin's superficial layer (epidermis). It helps support the skin, heal wounds and keep the nails and hair healthy.

- ***Dermatophytes mostly infect the keratinized stratum corneum of the epidermis.***
>Tinea pedis which is caused by the dermatophyte- **trichophyton rubrum** is limited to the stratum corneum layer. The only exception to this is patients who are immunocompromised.

![page_1.jpg](https://images.hive.blog/DQmQ3RQDEZoJhT7abaAg2t8YDFgCEH4VdtbWJyeuuDwRUEf/page_1.jpg)

**Low Immune Respone**

![page_1.jpg](https://images.hive.blog/DQmUdpbS3CtU63uAY77qsQZGWwXjv3CQJyBEvikp6XUv1Gy/page_1.jpg)

The penetration of a pathogen into a tissue leads to a corresponding immune response.
This means that the penetration of trichophyton rubrum to the skin(stratum corneum) leads to innate and specific immune responses which are  
**neutrophilic granulocytes, macrophages, antibodies and T cells**.

You can only be attacked by a dermatophyte when you have a **low immune response**. Since tinea pedis(athlete foot) is a contagious disease, spores of **TRICHOPHYTON RUBRUM** can get attached to your skin from an infected surface or from an infected person and you become affected when your immune response is low.



***Trichophyton rubrum(T.rubrum)***



![page_1.jpg](https://images.hive.blog/DQmaTzAXXZYLvPSbvsjxtRJEmK4jqj93jFmt7Zg8Lr1DCiA/page_1.jpg)



A Dermatophyte is a group of parasitizing filamentous fungi that is able to infect the keratinized tissues such as the stratum corneum of the epidermis,nails and hairs.

Trichophyton rubrum is a type of dermatophyte which is mainly responsible for the skin disease 'tinea pedis '-athlete foot. Trichophyton rubrum caises 70% of athlete foot infection in humans. Others like Trichophyton interdigitale , Epidermopyhton floccosum and Microsporum specie are responsible for the remaining 30% athlete foot infection.
**Trichophyton rubrum is the one mostly responsible for athlete foot.**
 
Trichophyton rubrum causes fungal infection(athlete foot) and this makes us understand that it is a harmful fungi. Trichophyton rubrum can be found in dirty places. It has the ability to grow in moist and warm environment. Dirty places gives trichophyton rubrum the ability to attach to one's skin. 

***PATHOGENESIS OF TINEA PEDIS***


![page_1.jpg](https://images.hive.blog/DQmT2ybzQTrinSvWztHgc61jg2MRsw4hzE2NCs8ePRtqiru/page_1.jpg)

Pathogenesis of tinea pedis involve the following steps which include:
- Contact
This is the first stage involved in the development of tinea pedis. Since tinea pedis is contagious,the spores(arthroconidia) of trichophyton rubrum can get attached to ones skin through **contact** with an infected surface or person.

- Adherence( colonization)

This stage involves the adherence of fungal elements capable of growth to the stratum corneum. When the vital fungal element (arthroconidia) attach long enough to the stratum corneum, growth takes place. The **hyphae** of the trichophyton rubrum then develops and begin to spread over the lower layers of stratum corneum horizontally and perpendicularly.

>Fungal elements include the arthroconidia and hyphae
*UV exposure might possibly direct the direction of growth of the hyphae into the depth* 

- Invasion
Invasion here means 'taking over'. The dermatophytes here are taking over the keratin layer.
Invasion is accompanied by a release of **fungal enzymes and other pathogenic factors** .The dermatophyte secrets an enzyme called keratinases. **Keratinases** degrade the hard keratin into components of low molecular weight which can be used by the dermatophyte(trichophyton rubrum).

Trichophyton rubrum cell wall contains  a pathogenic toxin called **mannans**, which suppresses the body's immune response. The role of the mannans is that it reduces keratinocyte proliferation, resulting in a decreased rate of sloughing and a chronic state of infection

As I said earlier, the pathogenesis of tinea pedis is how the infection(tinea pedis)develops.
 
**Risk Factors of Tinea pedis**
Risk factors are factors that can increase the risk of getting tinea pedis(athlete foot). These risk factors include:

- Warm and moist environment:
A warm and moist environment is very suitable for fungi, it also aids the growth of fungi (trichophyton rubrum). A moist environment can be gotten from 
frequent wear of enclosed footwear.

- sharing of mats, shoes, clothes or bedlinen with someone who has athlete foot

- Walking bare foot in public area e.g swimming pools, public bathroom e.t.c

- A poor immune system such as in immunocompromised individuals
 

       
![page_1.jpg](https://images.hive.blog/DQmfC7hJrKXe7cbCg6YfwPwLkSu2fHc9DpxWvEMsrMH9YZ1/page_1.jpg)

   *Thanks for stopping*

Look forward for the continuation of **TINEA PEDIS** in my next post