Derma Case: 33-year-old Man with Rash on Elbows and Knees

00:01 Our next topic for the day is psoriasis So, a 33-year-old man with no past medical history presents with persistent rash on his elbows and his knees.

00:13 He's noticed similar lesions in these areas at various times over the past several years, but they typically resolved spontaneously in the summertime, or with the assistance of some over-the-counter topical steroid.

00:25 He also notes an itchy area on the back of his head and wonders if that's related. Denies any fevers or chills, no oral lesions, no history of allergens. He works as a mechanical engineer and he's not exposed to any chemicals. He smokes a pack a day, rare alcohol use.

00:43 He does have an uncle with ankylosing spondylitis.

00:46 No arthralgias and no eye symptoms. So let's review this case and look at a few important details. First off, the time course sounds chronic and vacillating. He says it's been coming at various times over the past several years, and this is just one more presentation with his symptoms. Second, the pattern of skin involvement sounds symmetric.

01:06 He's having lesions on both elbows, both knees. He's also having some lesions on his scalp. Next up, skin information.

01:14 Until we get a physical exam, it's going to be hard for us to say that.

01:18 At least he's not reporting any tender lesions or any pustules or anything like that. And last, systemic involvement.

01:25 He's got a pretty negative review of systems. There's no fevers or constitutional symptoms, so it seems like this is purely a skin disease, at this point.

01:33 Okay, let's take a look at the physical exam. So we have multiple, well-demarcated, erythematous plaques with thick, silvery scale on the extensor surface of his elbows and, shown here, his knees.

01:45 Now scraping off one of those plaques causes punctate bleeding.

01:50 We'll have to figure out what that means later. A similar 4x3 cm plaque is noted on the posterior scalp. And when we review his fingernails and toenails, we see multiple nail pits on the fingernails, and there's also onycholysis noted on several toes, as shown here on the bottom right.

02:07 Okay. This is going to be the easiest case ever.

02:10 This case screams psoriasis, not to mention the fact that this video is called psoriasis.

02:16 So let's go ahead and take a look at my list of options.

02:20 Oh, snap. That is a lot of different types of psoriasis.

02:25 I guess we'll have to go through each one in turn: pustular, inverse, erythrodermic, guttate, and plaque psoriasis.