Dermatomyositis and Seborrheic Dermatitis

00:01 Let's move on to dermatomyositis.

00:03 So this is a disease afflicting generally patients who are a bit older than our patient, generally over the age of 50.

00:09 It's associated with proximal muscle weakness of the arms and the legs.

00:14 There's a number of different skin manifestations that we may find, Gottron's papules are shown here, one of the classic manifestations.

00:21 The shawl sign or the V-sign which is shown here as well on the right.

00:25 Then there's this heliotropic rash.

00:27 Now our patient does have this rash over the zygomatic processes of the face.

00:31 It's not really going on around the eyes, however, even though we do have some evidence of blepharitis.

00:37 More importantly, if a patient was being considered for dermatomyositis, we really should have some myositis.

00:44 And we're not getting any of that sort of picture nor any other manifestations of this disease.

00:49 Moreover, the facial rash of dermatomyositis lacks that bright erythema that we're seeing in our patient.

00:55 Either way, we can keep that one on our list but again, I think it's a little bit lower down in our differential.

01:01 Alright, seborrheic dermatitis.

01:04 This is a chronic, relapsing, mild dermatitis of unknown etiology though there are some associations with malassezia.

01:12 It's common in infants and in adults and particularly in those who are HIV positive.

01:18 It can have a prefilection for the scalp, behind the ears, the eyebrows, the nasolabial folds, the upper chest and the back, the ears, and certainly it can be associated with blepharitis.

01:30 Usually, these lesions are relatively well-demarcated.

01:34 They're scaly, flaky, somewhat itchy often described as greasy-looking plaques.

01:40 The lesions that we're seeing in our patient however, are more erythematous than having this greasy appearance of seborrheic dermatosis.

01:48 So I think we can safely take that one off our list as well.