DERMATOMYOSITIS

SUMMARY

1. Dermatomyositis (DM) is similar to polymyositis (PM) but skin involvement can be severe.

2. Consist of a moderate-to-deep, purple-red, papular, sometimes scaly, photosensitive rash that occurs on the face, neck ("V sign" or "shawl sign"), and extensor surfaces of the joints.

3. There is an associated periorbital oedema with a heliotrope rash, which is violaceous and classically appears on the upper eyelids.

4. Gottron papules are flat-surfaced, reddish-to-violet, scaling papules on the knuckles, elbows & knees (these actually look more like "cigarette-paper" crinkling over the MCPs).

5. Abnormally raised CK (thousands), abnormal EMG, muscle bx (gold standard), bx of Grotton papules.

6. assoc. with ovarian, lung, pancreatic, colon CA and lymphoma. Strong association when anti-p155/p140 Ab positive.

Reference(s)

Wilkinson, I., Furmedge, D. and Sinharay, R. (2017). Oxford handbook of clinical medicine. Oxford: Oxford University Press. Get it on Amazon.
Feather, A., Randall, D. and Waterhouse, M. (2020). Kumar And Clark’s Clinical Medicine. 10th ed. S.L.: Elsevier Health Sciences. Get it on Amazon.
Hannaman, R. A., Bullock, L., Hatchell, C. A., & Yoffe, M. (2016). Internal medicine review core curriculum, 2017-2018. CO Springs, CO: MedStudy.
Therapeutic Guidelines. Melbourne: Therapeutic Guidelines Limited. https://www.tg.org.au [Accessed 2021].