A site for medical students - Practical,Theory,Osce Notes

Examination of skin lesions an OSCE guide

1. Use good lighting: preferably natural lighting.
2. Patient is adequately exposed.
3. Comment on:              
  • Type of the lesion—primary and sequential: colour.
  • Shape of the lesions.
  • Arrangement of two or more lesions.
  • Distribution of the lesions—examine specifically the hair, nails and mucous membranes.
4. Do palpation to confirm findings.
5 Tell the probable diagnosis.
6. Do or tell one specific test to clinch the diagnosis.
1. Primary lesions They could lie
  • Flat (in the plane of the skin): Macule.
  • Elevated (above the plane of the skin): Papule, plaque, vesicle, bullae, pustule, cyst, wheal.
  • Depressed (below the plane of the skin): Ulcer, erosion.
2. Sequential lesions (occur over a primary lesion) Scaling, dry or wet exudation or llchenification.
3. Shape Round, oval, annular, iris, serpiginous, umbillicated. polygonal or polycyclic.
4. Arrangement herpctiform. zosteriform. reticular, linear or serpiginous.             '
5. Distribution Symmetrical or asymmetrical, exposed areas, intertriginous areas, sites of pressure, local or generalised.
6. Specific tests Include microscopic examination of the scales, crusts or exudate. Tzanck test. Auspltz sign. Nikolsky's sign. Koebner's phenomenon, patch test. etc.
7. The manifestations of a few common diseases are:
  • Iris lesion or target lesion: Erythema multlforme.
  • Annular lesions with scaling: Dermatophytosts. psoriasis and pityriasis rosea.
  • Annular lesions without scaling: SLE. Secondary syphilis.
  • Bilateral symmetrical eruptions: Drug or endogenous  hypersensitivity
  • On exposed areas: Pellagra, photosensitivity.
  • On interlriginous areas: Candidiasis.
  • On sites of pressure: Psoriasis.
  • Velvety brown pigmentation of the axilla and groins: Acanthosis nigricans.

This is very important for students preparing for USMLE and MRCP