Let's talk about pityriasis rosea first.
First off, even though we're talking about the
fungal infections of the skin conversation,
it turns out that this is not a fungal infection.
In fact, pityriasis rosea is completely
idiopathic, we don't know exactly what causes it.
It is self-limited, it's gonna go away on its own.
It's pruritic and you'll have oval maculopapules
that are distributed over the chest or back
in a so-called 'christmas tree' pattern.
It's kind of illustrated here on the right.
These are scaly, maculopapules as well.
Now I mentioned it's idiopathic but
it is postulated that there might be
some sort of viral etiology for this
condition that just hasn't been identified yet
particularly since it seems to often be associated
with some nonspecific viral URI symptoms
The jury is still out on that one.
And secondly, while this may not
look much like what our patient has,
it is important to note that patients with this condition
often present with a single solitary 'herald patch'
like this one, it's about 2-6 cm in
size described with central clearing,
a colorative scale, kinda looks
familiar to what our patient has, right?
Of note, for the majority of the times, the herald patch appears
somewhere else on the body like on the chest, or the back.
But in this case of this picture,
it's appearing on the ankle.
Importantly, as this disease is self-limited,
there typically is no treatment.
Patients should be advised however the
rash could persist up to 2 or 3 months.
Alright, I think we'll leave pityriasis
rosea on our list, knowing that
that herald's patch could be similar
to what our patient is experiencing.