Overview of Fungal Skin Infections | Tinea Infections

Summary

This educational video delves into tinea infections, commonly known as fungal skin infections. It covers various types of tinea, including athlete's foot (tinea pedis), ringworm (tinea corporis), scalp infection (tinea capitis), jock itch (tinea cruris), and nail infection (tinea unguium). The video explains the clinical presentations, diagnosis through KOH preparation, and treatment options. It highlights special cases like tinea capitis and tinea unguium, which may require oral antifungal treatments or specific topicals like efinaconazole, diverging from typical topical antifungal therapies.

Takeaways

• 🌿 Tinea infections are caused by fungi known as dermatophytes, primarily from the Trichophyton or Epidermophyton genus.
• 🔬 The pathophysiology of tinea involves the fungi metabolizing keratin in the skin, nails, and hair, leading to lesions and other symptoms.
• 📍 Tinea infections are named based on the body location affected, such as tinea corporis for the trunk, tinea pedis for the feet, and so on.
• 🦶 Tinea pedis, or athlete's foot, is the most common tinea infection, presenting as interdigital, hyperkeratotic, or vesiculobullous.
• 🐍 Tinea corporis, also known as ringworm, presents as circular/oval, pruritic, and scaling patches or plaques on the body.
• 🧢 Tinea capitis affects the scalp and can cause hair loss, itching, and scaling, often transmitted through direct contact.
• 🩲 Tinea cruris, or jock itch, is a fungal infection of the groin area, more common in men, and can be associated with sweating, diabetes, obesity, and immunodeficiency.
• 💅 Tinea unguium, or onychomycosis, affects the nails, causing them to become brittle, yellowish, and opaque with debris underneath.
• 🔬 Diagnosis of tinea infections typically involves a KOH preparation of skin scrapings to visualize segmented hyphae, or it may be based on clinical presentation.
• 💊 Treatment usually involves topical antifungals with a '-azole' suffix, but special cases like tinea capitis and tinea unguium may require oral antifungals or specific topical treatments like efinaconazole.

Q & A

What are tinea infections?

Tinea infections, also known as fungal skin infections, are caused by fungi known as dermatophytes, specifically from the genus Trichophyton or Epidermophyton.

How do dermatophytes cause tinea infections?

Dermatophytes cause tinea infections by metabolizing the protein keratin found in our skin, nails, and hair, leading to lesions, scarring, brittleness of nails, and dryness.

What are the different types of tinea infections based on body location?

Tinea infections are named based on the body location they affect: tinea corporis (trunk), tinea pedis (feet), tinea capitis (head), tinea cruris (groin), and tinea unguium (nails).

What is the most common clinical presentation of tinea pedis?

The most common clinical presentation of tinea pedis, or athlete's foot, is interdigital tinea pedis, which is itchy and scaly.

How is tinea corporis different from other tinea infections?

Tinea corporis, also known as ringworm, affects the trunk and is characterized by circular/oval, itchy, and scaling patches or plaques that spread centrifugally.

What is tinea capitis and how is it transmitted?

Tinea capitis is a fungal infection of the head, often leading to hair loss, itching, and scaling. It is transmitted through direct contact.

Why is tinea cruris more common in men than women?

Tinea cruris, or jock itch, is more common in men due to factors like excessive sweating, which is more prevalent in the groin area of men, especially those who are very active.

What are the clinical characteristics of tinea unguium?

Tinea unguium, or onychomycosis, presents as a crumbling, brittle nail with a yellowish, opaque appearance and unusual hyperkeratotic debris underneath the nail.

How are tinea infections typically diagnosed?

Tinea infections are typically diagnosed through a KOH (potassium hydroxide) preparation of skin scrapings, where segmented hyphae are visualized.

What are the treatment options for tinea infections?

Treatment for tinea infections usually involves topical antifungals with a '-azole' suffix, such as fluconazole or butenafine. However, special cases like tinea capitis and tinea unguium may require oral antifungals or specialized topical treatments like efinaconazole.

Why are oral antifungal treatments sometimes avoided for tinea unguium?

Oral antifungal treatments for tinea unguium are sometimes avoided due to potential liver toxicity issues, leading to a preference for topical treatments like efinaconazole.

Outlines

00:00

🦠 Overview of Tinea Infections

This paragraph introduces fungal skin infections, also known as tinea infections, caused by dermatophytes like trichophyton and epidermophyton. The fungi metabolize keratin in skin, nails, and hair, leading to lesions, scarring, and dryness. Tinea infections are named based on the affected body part: tinea corporis (trunk), tinea pedis (feet), tinea capitis (head), tinea cruris (groin), and tinea unguium (nails).

05:01

👣 Tinea Pedis (Athlete’s Foot)

This section explains tinea pedis, or athlete’s foot, the most common dermatophyte infection. It can present in three ways: interdigital (between the toes), hyperkeratotic (on the soles), and vesiculobullous (on the medial foot). All presentations can be itchy and may involve scaling or pain. Visual descriptions highlight scaling and affected areas.

🔵 Tinea Corporis (Ringworm)

Tinea corporis, also known as ringworm, affects the trunk (excluding hands, feet, groin, and face). It manifests as pruritic (itchy) circular or oval, scaling patches or plaques that spread centrifugally (from the center outward). Lesions are well-demarcated and can enlarge over time.

🧢 Tinea Capitis (Scalp Infection)

Tinea capitis is a fungal infection of the scalp that leads to patchy hair loss and scaling. It is transmitted through direct contact, meaning it can spread between individuals. A memory aid is provided: 'cap' for the head.

🤾‍♂️ Tinea Cruris (Jock Itch)

Tinea cruris, or jock itch, affects the groin area and is more common in men. It begins on the inner thighs and spreads centrifugally. This condition is erythematous (red), well-demarcated, and often associated with excessive sweating, diabetes, obesity, or immunodeficiency.

💅 Tinea Unguium (Nail Infection)

Tinea unguium, also known as onychomycosis, is a fungal infection of the nails, leading to brittle, crumbling, yellowish, opaque nails with hyperkeratotic debris underneath. An entire lecture on this topic is available for more detailed information.

🔬 Diagnosing and Treating Tinea Infections

Tinea infections are diagnosed through clinical presentation or by KOH skin scraping preparation to visualize segmented hyphae. Treatment typically involves topical antifungals ending in '-azole' (e.g., fluconazole or butenafine). Two special cases (tinea capitis and tinea unguium) may require oral antifungals or efinaconazole due to their severity.

📚 Additional Dermatology Resources

The speaker concludes by encouraging viewers to explore more dermatology-related topics through a dedicated playlist. This serves as an invitation for further learning on various skin conditions.

Keywords

💡Tinea infections

Tinea infections, also known as fungal skin infections, are caused by dermatophytes, which are a type of fungi. These infections are a central theme of the video, as they affect various parts of the body and present in different forms. The video discusses various types of tinea infections, such as tinea pedis (athlete's foot) and tinea corporis (ringworm), and their specific characteristics.

💡Dermatophytes

Dermatophytes are the fungi responsible for tinea infections. They belong to the genera Trichophyton or Epidermophyton. The video explains that these fungi metabolize keratin, a protein found in the skin, nails, and hair, leading to the clinical manifestations of tinea infections. This term is crucial for understanding the etiology of the conditions discussed.

💡Keratin

Keratin is a protein that is a primary component of the skin, hair, and nails. In the context of the video, dermatophytes metabolize keratin, which results in the various symptoms seen in tinea infections, such as lesions, scarring, and brittle nails. This process is fundamental to understanding the pathophysiology of the infections.

💡Tinea corporis

Tinea corporis, also known as ringworm, is a specific type of tinea infection that affects the trunk of the body. The video describes it as pruritic and scaling, often presenting as a circular or oval patch. It spreads centrifugally, meaning it grows outward from the center. This term is used to illustrate one of the various clinical presentations of tinea infections.

💡Tinea pedis

Tinea pedis, commonly referred to as athlete's foot, is highlighted in the video as the most common dermatophyte infection. It presents in different clinical forms, such as interdigital (between the toes), hyperkeratotic (soles of the feet), and vesiculobullous (medial foot). The video emphasizes its prevalence and the various ways it can manifest.

💡Tinea capitis

Tinea capitis is a fungal infection of the scalp and hair, often leading to hair loss, itching, and scaling. The video notes that it is more commonly transmitted through direct contact. This term is significant as it represents a type of tinea infection that requires different treatment considerations compared to other forms.

💡Tinea cruris

Tinea cruris, known colloquially as jock itch, is a fungal infection of the groin area. The video points out that it predominantly affects men and is associated with factors like excessive sweating, diabetes, obesity, and immunodeficiency. This term is important for understanding a specific type of tinea infection that has unique risk factors.

💡Tinea unguium

Tinea unguium, also called onychomycosis, is a fungal infection of the nails. The video describes it as causing the nails to become brittle and yellowish, with hyperkeratotic debris under the nail. This term is crucial for understanding a form of tinea infection that affects the nails and requires specialized treatment.

💡KOH preparation

KOH preparation, or potassium hydroxide preparation, is a diagnostic method mentioned in the video for identifying tinea infections. It involves examining skin scrapings under a microscope after treating them with KOH to reveal the presence of segmented hyphae, which are indicative of fungal infection. This term is key to understanding how these infections are diagnosed.

💡Topical antifungals

Topical antifungals are medications applied directly to the skin to treat tinea infections. The video mentions that most cases of tinea infections are treated with topical antifungals, which often have a '-azole' suffix, such as fluconazole or butenafine. This term is central to understanding the typical treatment approach for these conditions.

💡Terbinafine

Terbinafine is an oral antifungal medication highlighted in the video for treating tinea capitis. It is one of the special cases where an oral treatment is preferred over topical antifungals. This term is important for understanding the treatment of certain tinea infections that require systemic medication.

Highlights

Introduction to fungal skin infections, known as tinea infections, caused by dermatophytes from the genus Trichophyton or Epidermophyton.

Tinea infections affect the skin, nails, and hair by metabolizing keratin, leading to lesions, scarring, brittleness of nails, and dryness.

Tinea infections are named based on the location: tinea corporis (trunk), tinea pedis (feet), tinea capitis (head), tinea cruris (groin), and tinea unguium (nails).

Tinea pedis (athlete's foot) is the most common dermatophyte infection, presenting as itchy, scaly, and affecting areas between the toes or soles.

Different forms of tinea pedis include interdigital (between toes), hyperkeratotic (soles), and vesiculobullous (medial foot, painful and pruritic).

Tinea corporis (ringworm) affects the body except for hands, feet, groin, and face, presenting as circular or oval scaling patches or plaques that spread centrifugally.

Tinea capitis affects the scalp, causing hair loss, itching, and scaling, and is spread through direct contact.

Tinea cruris (jock itch) occurs in the groin area, more common in men, and often associated with sweating, diabetes, obesity, and immunodeficiency.

Tinea unguium (onychomycosis) affects nails, causing them to become brittle, yellow, and opaque, with hyperkeratotic debris underneath.

Diagnosis of tinea infections is often done through clinical presentation or a KOH preparation showing segmented hyphae in skin scrapings.

Treatment typically involves topical antifungals, particularly medications ending in '-azole,' such as fluconazole and butenafine.

Two special cases of tinea infections require oral antifungals or extended treatment: tinea capitis (scalp) and tinea unguium (nails).

Terbinafine or griseofulvin is used for treating tinea capitis, while efinaconazole is favored for long-term treatment of tinea unguium.

Oral antifungals for tinea unguium are being avoided due to liver toxicity concerns, leading to a shift towards topical efinaconazole.

A mnemonic for remembering special cases: the head (capitis) and the toes (unguium) are the extreme points where oral or extended treatment is required.

Transcripts

Hey everyone! This lesson is on an overview  of fungal skin infections, or otherwise known  

as tinea infections. So in this lesson we will  be talking about a variety of different tinea  

infections, so we're going to go over their  clinical presentation, how we diagnose them,  

and finally how we treat them. So tinea infections  are infections by fungi known as dermatophytes,  

and they come from the genus trichophyton or  epidermophyton. Here are the images of those  

trichophyton and epidermophyton fungi. Now the  pathophysiology of tinea infections involves the  

fungi metabolizing the protein keratin in our skin, nails and hair - this is how they actually present  

and why they actually look the way they do because  fungi metabolize keratin it leads to lesions,  

scarring, brittleness of the nails, and dryness that  type of clinical picture. Now, the tinea infections  

are actually named depending on body location.  If there is any infection on the trunk, it's  

known as tinea corporis. If it's an infection on the  feet, it's tinea pedis, if it's an infection on the  

head it's tinea capitis. If it's an infection of  the groin, it is tinea curries, and if it's an infection  

of the nail, it is known as tinea unguium. So we're going to  talk about each of these in more detail in the  

next couple slides. So the first one we're talking  about is tinea pedis, otherwise known as athlete's foot.

This is probably a very common one that many  people know about and probably have had. It is the  

most common dermatophyte infection and it presents  in a few different clinical presentations. The first

one is the most common presentation - it is  interdigital tinea pedis. This is the most  

common type - it's itchy (pruritic) and it's scaly. So we can see  in this image here again it's very scaly looking.  

 Another presentation is a hyperkeratosis. It's erythematous

but mostly involves the soles of  the feet and the other one is a vesiculobullous  

eruption, and again this can be pruritic, so  itchy, but can also be very painful and it happens on the  

medial foot. So interdigital is between the toes. Hyperkeratotic  occurs on the soles of the  

feet and then the vesiculobullous eruption occurs  on the medial foot. So again, if we take a look at this  

image here we can see noticeable scaling in  this interdigital presentation. Now the next one  

we're going to talk about is tinea corporis. Tinea corporis is also known as ringworm, and again this one  

affects the trunk. So when we say trunk, it really  basically means anywhere on the body except the  

hands, the feet, the grown or the face. And this  one is also pruritic (itchy) and as you can see in the  

image, it is circular/oval in shape and it too is  also a scaling patch or plaque. So it's a patch or  

plaque. A patch is a flat surface or flat lesion  that's greater than one centimeter and a plaque is  

a raised lesion greater than one centimeter and  it spreads centrifugally - so it really means  

that it spreads from the inside, outwards so it can  continually get larger and larger from its central  

location. So again, we take a look at the image here  it's a demarcated, very well demarcated, circle or  

oval, and when we take a look at the lesion itself,  it's a scaling patch or plaque. The next presentation  

we're going to talk about is tinea capitis. Tinea  capitis is a fungal infection of the head and an  

easy way to remember this is capitis, "cap", so you  can think of the cap or the top of your head or  

you can put a baseball "cap" on  your head. So this is how you can remember tinea  

capitis is an infection of the head. And this leads  hair loss and it too is also pruritic (itchy)  

and scaling and this one is actually more  related to a direct contact transmission. So if  

one person has tinea capitis, you can actually  have a transmission from that person to another  

individual so that they can have tinea capitis as well. So again, you see this patchy hair loss with  

this characteristic scaling appearance. The  next presentation we're talking about is tinea  

cruris. Tinea cruris is a fungal infection  of the groin area, and this is commonly known as  

jock itch. This affects men more than women,  and what happens generally in this presentation  

is that it begins on the medial thigh (so the  inner sides of the thighs), and it's also spread  

centrifugally, so it spreads from its center  outwards. It's also erythematous and elevated. So  

it becomes well demarcated because of this,  and it has associated factors involved: one  

is excessive sweating - so a lot of times this is  why it's a jock itch sometimes in men or someone  

that's very active where they can become  very sweaty in that area and it can lead to this  

jock itch. Other associated factors include diabetes  and obesity and also immunodeficiency, so all  

these can relate to getting jock itch or recurrent  jock itch or recurrent tinea cruris. And the last  

presentation to talk about is tinea unguium.  This one is basically a fungal infection of the  

nail. I have an entire lecture on this topic  if you want more information. It's also called  

onychomycosis. It is basically a crumbling, brittle  nail just because the fungi are actually digesting  

away the nail itself. It leads to a yellowish,  opaque nail and if you're to take a look  

underneath the nail you get some unusual hyperkeratotic debris. So now that we've seen a variety  

of clinical presentations of tinea infections, how  are they diagnosed? The diagnosis involves  

doing a KOH preparation of skin scrapings and  what you would see is you would visualize segmented hyphae

- so you'd see an image like this and you  would see these segmented hyphae. So  

a lot of times we don't do this, it may just be a clinical diagnosis (clinical presentation) of the tinea infection.  

So once we've made the diagnosis, how do we treat it?  Treatment typically involves topical antifungals  

or medications with "-azole" at the end of their name.  With the "-azole" suffix, you can think of medications  

like fluconazole and another one might be butenafine. So majority of cases of  

tinea infections are treated with  topical antifungals but there are two special  

cases I want you to think about and I'll tell  you a way to remember them in a moment. So the two  

special cases are tinea capitis (tinea capitis  so the top of your head) we're going to typically use  

terbinafine or griseofulvin. And the second one is  tinea unguium (or the fungal infection of the nail),  

and we're going to generally either use an oral  antifungal or efinaconazole for a  

very long period of time about 48 weeks (so a  lot of time). We've been moving away from oral  

antifungal just because of some liver toxicity  issues, so we're more going toward efinaconazole,  

which is also a topical treatment but it's a more  special topical treatment for tinea unguium. So these are  

the two special cases and I told you I'd tell  you a way to remember them that the top of your  

head and your fingers so they're basically the  extremes right? So the top of your head, the the  

highest up you're going, it's basically the  extreme of your height, and all the way down to  

the bottom of your feet at the tip of your toes  is the other special case, and those are the two  

types of fungal infections that you're going to have  to use something else other than just the typical  

topical antifungal. If you also want to learn  more about other dermatology conditions please  

check out my dermatology playlist. Thanks so much for watching and I hope to see you next time!