1/
OK team, #tweetorial #3 in our #Derm101 series on the #dermatology exam. Today, let's discuss:
CONFIGURATION!
How primary lesions are grouped or shaped. Read on to learn more!
#dermtwitter #medtwitter #medstudentwitter #meded #FOAMEd pc:@dermnetnz @BrwnSkinMatters
OK team, #tweetorial #3 in our #Derm101 series on the #dermatology exam. Today, let's discuss:
CONFIGURATION!
How primary lesions are grouped or shaped. Read on to learn more!
#dermtwitter #medtwitter #medstudentwitter #meded #FOAMEd pc:@dermnetnz @BrwnSkinMatters
2/
Since this is the 3rd installment in the #Derm101 series, remember that if you haven't already, you might want to check out the first two #tweetorials on skin morphology.
Primary Lesion:
Secondary Lesion:
Since this is the 3rd installment in the #Derm101 series, remember that if you haven't already, you might want to check out the first two #tweetorials on skin morphology.
Primary Lesion:
Secondary Lesion:
3/
I think of configuration as how the primary lesion might be shaped or grouped. So this would include rashes that are:
Annular
Polycyclic
Serpiginous
Linear
Geometric
Agminate
Herpetiform
Sporotrichoid
Target/Targetoid (kind of)
What configuration was the rash in tweet #1?
I think of configuration as how the primary lesion might be shaped or grouped. So this would include rashes that are:
Annular
Polycyclic
Serpiginous
Linear
Geometric
Agminate
Herpetiform
Sporotrichoid
Target/Targetoid (kind of)
What configuration was the rash in tweet #1?
4/
That first photo is one of tinea corporis, which is a superficial dermatophyte infection. It's ANNULAR, which means there is a ring/circle of inflammation.
Remember that in darker skin, the erythema disappears, but the secondary lesions may still stick around (like scale).
That first photo is one of tinea corporis, which is a superficial dermatophyte infection. It's ANNULAR, which means there is a ring/circle of inflammation.
Remember that in darker skin, the erythema disappears, but the secondary lesions may still stick around (like scale).
5/
Other things can be annular!
Here are granuloma annulare (1) & erythema annulare centrifugum (2).
Why isn't this tinea?
Well, tinea should be scaly, whereas GA is dermal, so there shouldn't be scale, and in EAC, scale is on the trailing (inside) edge (instead of outside).
Other things can be annular!
Here are granuloma annulare (1) & erythema annulare centrifugum (2).
Why isn't this tinea?
Well, tinea should be scaly, whereas GA is dermal, so there shouldn't be scale, and in EAC, scale is on the trailing (inside) edge (instead of outside).
6/
These details often give away the dx. (Isn't derm amazing?!)
OK👉POLYCYCLIC rashes are like annular rashes but the rings aren't always complete and can join together! See this👇 example of EAC!
@HarkerDavid recently shared a great example of EAC too:
These details often give away the dx. (Isn't derm amazing?!)
OK👉POLYCYCLIC rashes are like annular rashes but the rings aren't always complete and can join together! See this👇 example of EAC!
@HarkerDavid recently shared a great example of EAC too:
7/
Next up, SERPIGINOUS, or snake like!
These are examples of Cutaneous Larva Migrans! A hookworm burrows into the skin from sand & soil and can't invade deeper because it lacks collagenase. So while treatment is usually antiparasitics, you can leave it alone and the worm dies!
Next up, SERPIGINOUS, or snake like!
These are examples of Cutaneous Larva Migrans! A hookworm burrows into the skin from sand & soil and can't invade deeper because it lacks collagenase. So while treatment is usually antiparasitics, you can leave it alone and the worm dies!
8/
Let's talk LINEAR and GEOMETRIC. If you say something is linear or geometric, we often are implying that it was an outside job - not something the body made itself, but reacting to something from the outside world.
A great example of a geometric rash from a bandaid is below.
Let's talk LINEAR and GEOMETRIC. If you say something is linear or geometric, we often are implying that it was an outside job - not something the body made itself, but reacting to something from the outside world.
A great example of a geometric rash from a bandaid is below.
9/
LINEAR could mean something brushed the skin & left vesicles in lines (poison ivy - 1)
It could also mean the patient induced a rash where they scratched (Koebner phenomenon - 2).
Or maybe they scratched themselves and auto-inoculated a wart in a line! (pseudo-koebner - 3)
LINEAR could mean something brushed the skin & left vesicles in lines (poison ivy - 1)
It could also mean the patient induced a rash where they scratched (Koebner phenomenon - 2).
Or maybe they scratched themselves and auto-inoculated a wart in a line! (pseudo-koebner - 3)
10/
When you say something is linear or geometric you inherently suggest something about how the lesion came to be.
One of the few examples of linear plaques that's an "inside job" is flagellate erythema, from 1 of 3 things:
1- dermatomyositis
2- bleomycin
3- shiitake mushrooms!
When you say something is linear or geometric you inherently suggest something about how the lesion came to be.
One of the few examples of linear plaques that's an "inside job" is flagellate erythema, from 1 of 3 things:
1- dermatomyositis
2- bleomycin
3- shiitake mushrooms!
11/ MID-TWEETORIAL RECAP
✅ Annular - ring of inflammation
✅ Polycyclic - similar DDX as annular, but with incomplete rings that might come together
✅ Linear and Geometric - implies outside job
✅ Outside job could be scratching, exposure to something
✅ Dermatology is awesome.
✅ Annular - ring of inflammation
✅ Polycyclic - similar DDX as annular, but with incomplete rings that might come together
✅ Linear and Geometric - implies outside job
✅ Outside job could be scratching, exposure to something
✅ Dermatology is awesome.
12/
Let's move on to AGMINATE.
Say what?!
All agminate means is grouped, or clumped together. So when a bunch of papules pop up together, You could say "agminated papules."
These are example of "phrynoderma," seen in Vit A deficiency!
pc: e-ijd.org/article.asp?is…
Let's move on to AGMINATE.
Say what?!
All agminate means is grouped, or clumped together. So when a bunch of papules pop up together, You could say "agminated papules."
These are example of "phrynoderma," seen in Vit A deficiency!
pc: e-ijd.org/article.asp?is…
13/
Similar to agminate, HERPETIFORM is a clustering together of lesions. Usually, we're talking about vesicles, and usually we're implying that it looks like herpes virus!
The clustering together of these vesicles is what gives the border the characteristic "scalloped" shape.
Similar to agminate, HERPETIFORM is a clustering together of lesions. Usually, we're talking about vesicles, and usually we're implying that it looks like herpes virus!
The clustering together of these vesicles is what gives the border the characteristic "scalloped" shape.
14/
SPOROTRICHOID implies that something is moving through your lymphatics causing lesions to pop up in that pattern on your extremity.
A mnemonic for this: CAT N SPLAT
Cat Scratch
Atypical mycobacteria
TB
Nocardia
Sporotrichosis
Phaeohyphomycoses
Leishaniasis
Anthrax
Tularemia
SPOROTRICHOID implies that something is moving through your lymphatics causing lesions to pop up in that pattern on your extremity.
A mnemonic for this: CAT N SPLAT
Cat Scratch
Atypical mycobacteria
TB
Nocardia
Sporotrichosis
Phaeohyphomycoses
Leishaniasis
Anthrax
Tularemia
15/
A brief interlude to point out how certain types of configuration implies certain diagnoses or pathophysiology.
Herpetiform 👉 Herpes virus
Sporotrichoid 👉 Something in lymphatics
Linear/geometric 👉 Outside job (usually)
A brief interlude to point out how certain types of configuration implies certain diagnoses or pathophysiology.
Herpetiform 👉 Herpes virus
Sporotrichoid 👉 Something in lymphatics
Linear/geometric 👉 Outside job (usually)
16/
Finally, TARGET vs. TARGETOID.
While some might disagree that these are "configuration," I do think they are adjectives for the primary lesion and describes a shape, so I've lumped them here.
How do you tell them apart?
Finally, TARGET vs. TARGETOID.
While some might disagree that these are "configuration," I do think they are adjectives for the primary lesion and describes a shape, so I've lumped them here.
How do you tell them apart?
17/
The zones of color differentiates a TARGET (3 zones) from a TARGETOID lesion (2 zones). We'll also call targetoid, "atypical targets."
So in the pic 1, the left is TARGET (red-white-red), the right is TARGETOID (red-dusky).
Target lesions look like the logo for target!
The zones of color differentiates a TARGET (3 zones) from a TARGETOID lesion (2 zones). We'll also call targetoid, "atypical targets."
So in the pic 1, the left is TARGET (red-white-red), the right is TARGETOID (red-dusky).
Target lesions look like the logo for target!
18/
Having target or targetoid lesions can change your diagnosis! For example, erythema multiforme has target lesions, and SJS has targetoid lesions! Check out my first ever #tweetorial for more details:
Other things can be targetoid too, like Fixed Drug!
Having target or targetoid lesions can change your diagnosis! For example, erythema multiforme has target lesions, and SJS has targetoid lesions! Check out my first ever #tweetorial for more details:
Other things can be targetoid too, like Fixed Drug!
19/
Final RECAP:
✅Agminate - grouped/clustered together
✅Herpetiform - more specific for clustered vesicles usually, implies herpes virus
✅Sporotrichoid - implies lymphatic spread
✅Target vs. Targetoid - 3 vs 2 zones of color.
✅Configuration can influence your diagnosis!
Final RECAP:
✅Agminate - grouped/clustered together
✅Herpetiform - more specific for clustered vesicles usually, implies herpes virus
✅Sporotrichoid - implies lymphatic spread
✅Target vs. Targetoid - 3 vs 2 zones of color.
✅Configuration can influence your diagnosis!
20/20
Thanks for joining this #tweetorial on configuration! I hope the #Derm101 series is making the language of #dermatology easier!
As per usual, check out this video version in case that's better for you (and to hear me say "agminate" incorrectly)!
Thanks for joining this #tweetorial on configuration! I hope the #Derm101 series is making the language of #dermatology easier!
As per usual, check out this video version in case that's better for you (and to hear me say "agminate" incorrectly)!
