Diagnosis of skin diseases
By end of this lecture the student should be able to:
The key to a successful Rx is a correct Dx
Dermatological diseases are usually visible, so inspection is all that is needed for Dx
How to bring order to confusion:
Types of lesions
Primary skin lesions
2---
3-
4- Nodule : A larger & deeper lesion than a papule, e.g., erythema nodosum
5- Blisters
Eg of vesicles
6- pustule: A visible accumulation of pus, as in folliculitis.
7-
8- Purpura
E.g. of petechiae & ecchymosis
9-
10-
11- Telangectasia : Permanent visible dilation of superficial blood vessels in the skin as in rosacea
12- Comedo: A plug of keratin & sebum wedged in a dilated pilo-sebaceous follicle, there are 2 types; open (black heads) & closed (white heads), as in acne vulgaris.
Secondary skin lesions
1-Scale: Excess flakes of dead epidermal cells from the horny layer, could be mild as in chapping or severe as in psoriasis.
2) Crust: A collection of dried serum & cellular debris as in impetigo.
3-Erosion:
4-Ulcer
5-fissure:
6-Sinus :
7-Excoriation
8-Atrophy:
9-Scar:
10-Lichenification
Koebner’s phenomenon
Nikolsky's sign
Nikolsky's sign
Auspitz's sign:
Configuration of lesions
Arrangement of lesions
1- DIASCOPY:
In TB of the skin diascopy reveals an appearance called apple- jelly nodules.
2- Dermoscopy
Wood's lamp
Uses of WOOD’S lamp
4)MYCOLOGY SAMPLES
5)LAB. INVESTIGATIONS :
6) CYTOLOGY (Tzanck's smear):
7) PATCH TESTS:
8) PRICK TESTS:
9) HISTOLOGY & IMMUNOFLUORESCNCE:
