General Terminology

00:01 Welcome to dermatology.

00:02 Here, we’ll take a look at inflammatory disorders.

00:06 Our topic, first, we’ll begin with general terminology.

00:09 It will behoove you to spend a little bit of time to make sure that you have a proper understanding of the following descriptions.

00:16 You will see these descriptions either being described by your attending or in a clinical vignette, and this will then clue you in as to what kind of dermatologic condition you are referring to.

00:27 For example, if it’s a macule, you cannot feel this.

00:30 So therefore, you place your hand on the macule.

00:33 For example, café au lait spot.

00:35 It’s a macule, it’s mocha-colored.

00:37 By definition, less than one centimeter that is not palpable.

00:41 That is the most important topic.

00:44 Patch is a lesion that’s a little bit greater than 1 centimeter, and once again, that is not palpable.

00:50 Both of these are not palpable, but the size with the macule was a little bit smaller.

00:57 Once you get into papules, these are elevations.

01:00 And so therefore, it’s possible that you’re able to feel these, but the elevation here is less than one centimeter.

01:07 Or you might have a patient that has a condition we’ll talk about called psoriasis.

01:11 And psoriasis, this is a plaque, and this would be flat-topped elevation.

01:16 You’ve heard of salmon-colored plaque with psoriasis.

01:19 And here, the elevation would be greater than 1 centimeter.

01:23 A nodule, with nodule, I want you to think of something like a rheumatoid nodule or subcutaneous nodule that you might find with the criteria, Jones criteria, for rheumatic fever.

01:33 And so therefore, nodule will be round and with an elevation of less than 2 centimeters.

01:38 Whereas, if it’s a tumor, then remember, tumor, all it means is swelling.

01:43 And if it’s a particular tumor or swelling that has not developed due to, perhaps, injury or trauma, then you’re looking at an elevation of greater than 2 centimeters.

01:53 Then we get into what’s known as fluid-filled.

01:55 Now, what kind of fluid is then filling up your particular lesion? You’ve heard of herpes.

02:01 You’ve heard of chickenpox or varicella.

02:04 This is referring to your vesicle.

02:06 It’s a clear fluid blister, blister, blister.

02:09 You’ve heard of painful blisters that may occur with a condition, a porphyria pathway disease known as porphyria cutanea tarda, where that type of vesicle would then be painful in your patient upon exposure to UV light.

02:23 And here, the blister is less than 1 centimeter.

02:26 A pustule, I said pustule on purpose because here, you’re going to have fluid that’s filling up this blister, which is made up of pus, and we see pus less than 1 centimeter, and this is what you’re referring to.

02:39 Bulla.

02:40 A bulla, when we get into what’s known as your vesiculobullous or in other words, your bullous type of conditions, pemphigoid vulgaris or bulla pemphigoid.

02:51 A bulla is going to be fluid-filled as well but a little bit larger, greater than one centimeter in diameter.

02:57 Then we have erosions.

02:59 With an erosion, it’s a loss of part of the epidermis, part, erosion.

03:04 Whereas, if it’s an ulcer, that you’re going to then notice on the skin, then please understand the full thickness of loss of the epidermis.

03:13 The fine difference between erosion and ulcer becomes important to you in terms of description.