Hey everyone! This lesson is on the fungal skin infection known as jock itch. In this lesson,
we talk about what this condition is, we're also gonna talk about what causes it, some of the risk
factors for this condition, some of the signs of symptoms, how we can diagnose it, and how we
can treat it. So jock itch is also known as Tinea cruris - so here's an image of jock itch, and it
is a superficial skin infection of the groin area, of the crural fold, that's where that name comes
from. It's caused by fungi known as dermatophytes, and this condition may be confused with another
type of fungal skin infection known as intertrigo, which is caused by Candida, which is a yeast. So
jock itch is more likely to occur in males much more frequently than it is in females, and some
of the causative organisms of jock itch include the following: Number 1) is trichophyton rubrum;
the dermatophyte trichophyton rubrum is actually the most common causative organism of jock itch,
2) another one that we may see is something called trichophyton interdigitale, and we may also see
epidermophyton floccosum. So how is tinea cruris transmitted? Oftentimes, it is actually spread
from another fungal infection location mostly from tinea pedis or athlete's foot. So we can
get auto infection and what that means is that an individual who has athlete's foot can spread the
fungi from their feet into the groin area causing tinea cruris. And it can also be transmitted from
other humans, animals, and even soil. What are some of the factors that increase your risk for
getting this condition? The number one risk factor for getting tinea cruris (jock itch) is excessive
sweating. We can also see it being associated with physical activities that cause excessive sweating;
so related to the excessive sweating, physical activities that cause excessive sweating
particularly in the groin area can increase your risk for getting this condition being
male or being of the male gender is also another risk factor. So we talked about this before,
males are far more likely to have this condition than females. Being obese or overweight can
increase your risk for getting this condition. Diabetes, so having a systemic issue that causes
some immuno compromise, can increase your risk for this condition and again immunosuppression,
so it could be due to medications or it could be due to a systemic illness causing
immunosuppression. Tight fitted clothing can also increase your risk for this condition as well.
Poor hygiene in the area - so if you don't wash and dry properly you can have an increased risk
for getting this condition. Contact sport athletes are at a higher risk for this condition as well,
and there's also this genetic predisposition to having fungal infections in general - so if
for some reason you have decreased beta defensins like defensin beta 4, you're at an increased risk
for getting any infections in general and one of those is jock itch or tinea cruris. So what does
it actually look like? So here is jock itch - it often starts as an erythematous area in the medial
thigh - so medial thigh is the inner thigh - and it is pruritic, which means that it is itchy so
that's where the name comes from jock itch. And it is erythematous, which means that is reddened in
color, and it could be a patch, so if you were to feel it it might be flat or it could be slightly
elevated - that would be a plaque. And what we do find is that when it starts it starts to extend
outward with a centrifugal spread, so it spreads out, and the outer edge of this lesion might have
small little vesicles on it, and this lesion can spread into other areas of the groin including
the perineum and the gluteal cleft. And in males what is interesting is that the scrotum is often
spared in tinea cruris - this is going to help us distinguish it from another common fungal skin
infection, because we find that candida intertrigo affects the scrotum whereas tinea cruris does not.
So when we look at the skin lesion itself, we see that it is a clearly demarcated border,
which means that the difference between the lesion and the normal skin around it is a very clear,
distinct separation, and there may be a slightly raised edge to it with those small vesicles in
some cases. So again jock itch starts as a reddened and itchy skin lesion in the medial
thigh or the inner thigh, and it actually spreads outward from that location, outward centrifugally,
and it has a very well demarcated border as you can see here, and sometimes has small vesicles
at the outer edge of that border, and then spreads into other areas of the groin including
the perineum and gluteal cleft. But in males, it spares the scrotum, as opposed to intertrigo or
intertrigo, which affects the scrotum, so those are key characteristics of tinea cruris. So I
want to quickly talk about Candidal intertrigo or Candidal intertrigo because this condition
can often be confused with jock itch. Candido intertrigo occurs in the area where skin rubs on
skin so the intertriginous areas - so that's what that means where skin rubs on skin - so it can
affect areas like the groin, the axilla (so under the armpits), the panis, so panis could be where
an individual has a very large abdomen and the under part of the abdomen is rubbing on another
part of the skin that can cause or increase your risk for getting this infection. And inframammary,
which is under the breasts; all these areas can be affected by Candidal intertrigo. So because
Candidal intertrigo can affect the groin, it can be confused with tinea cruris. So what are some
ways that we can distinguish these two infections. So for one, Candidal intertrigo affects areas
where skin rubs on skin that might not help out with jock itch when we're trying to distinguish
this but what's important here is that in males intertrigo can affect the scrotum whereas with
jock itch the scrotum is not affected. So that's another way we can distinguish these two. And the
look of Candidal intertrigo looks a bit different as well. Oftentimes its moist, it's a reddened
area there's some skin breakdown there may even be some discharge from the site so it looks a little
bit wet as opposed to tinea cruris, which is often more dry. And the patient describes burning and
they may also have some itching sensation there as well. And what's important with regards to
both treating and preventing Candidal intertrigo is that cleaning and keeping the area dry are key
factors to preventing this condition in the first place. So again, intertrigo may be confused with
tinea cruris or jock itch but there's a couple ways we can distinguish the two; intertrigo occurs
where skin rubs on skin, and the scrotum is often affected in males; whereas in tinea cruris or jock
itch the scrotum is not affected. In tinea cruris, we see centrifugal spread, whereas in Candidal
intertrigo we don't see that centrifugal spread, we see it where the skin rubs on the skin and in
intertrigo we see skin breakdown and sometimes see discharge or a moist look to the skin,
which is different than in tinea cruris. So how do we diagnose and treat jock itch. So diagnosis of
jock itch is often a clinical one; we look at the skin lesion, and we look at their risk factors and
we determine that this is jock itch. We always have to think is this intertrigo? So again,
look at those ways that we distinguish the two. We could do a KOH wet mount looking at
skin scraping - so you take the skin scrapings use KOH and then you visualize segmented hyphae, and
this tells us that it is a fungal skin infection. The treatment of tinea cruris involves modifying
risk factors, that's a big thing here. We want to avoid getting tinea cruris later on in the future,
so we want to try to keep the area dry - you can use powders to do this and you want to avoid hot
baths, and as I mentioned before, a lot of times this is an auto infection - so an individual who
has tinea pedis can actually spread the fungi from their feet into the groin area, so you
want to treat concomitant tinea pedis and even treat concomitant onychomycosis or a fungal nail
infection. The way we actually do treat jock itch is by using topical antifungals, and importantly,
the way we treat intertrigo is using topical antifungals as well so even if you make a mistake
you can still use topical antifungals to treat both of these conditions and the topical anti
fungals are the "-azoles", naftafine, butenafine and oftentimes this may take up to three to four
weeks for effective treatment. And again nystatin is not effective in these cases - nystatin does
not treat dermatophyte infections - and if the topical antifungals don't work we can move on
to oral antifungals so we can use terbinafine and itraconazole. So again diagnosis is clinical - so
we look at the skin lesion, and we look at their risk factors and we make the diagnosis that way.
Or we could do a KOH wet mount, modify the risk factors, so important to modify risk factors,
keep the area dry, avoid some of those risk factors we talked about before, control your
blood sugars if you have diabetes, and important here is to treat concomitant co-occurring tinea
pedis infections. Topical antifungals are the first line (again nystatin it's not effective),
and then oral antifungals if the topicals are not effective. For more information on other fungal
skin infections, please check out my overview to fungal skin infections and my lessons on
athlete's foot and ringworm. If you like this video, please give it a thumbs up and consider
subscribing and as always continue to live, life, and learn and I hope to see you next time!