dermatology

1. History Taking, Physical
Examination, Investigation,
Psoriasis and Urticaria.

3. Layers of skin
• Epidermis
- Stratified squamous
epithelium
• Dermis
- Tough supportive
connective
tissue matrix.
- Has hair follicles and
sweat gland
• Hypodermis
- Has adipose tissue

4. Epidermis layer
a) Basal cell layer (Stratum basale)
b) Prickle cell layer (stratum
spinosum)
c) Granular cell layer (stratum
granulosum)
d) Stratum lucidum (thick skin
only)
e) Horny layer (stratum corneum)
Cells content type
- Keratinocyte
- Melanocyte
- Merkel’s cell
- Langerhans’ cell

5. Dermis
• Tough supportive connective tissue matrix.
• 0.6mm (eyelid) - 3mm (palm, back, sole)
• Collagen fibre make up 70% : support & strength
• Elastic fibres : elasticity to skin
• Ground substance is GAG : allow some movements
• Fibroblast : synthesize collagen, elastin
• Others: dermal dendrocyte, mast cells, macrophage
& lymphocytes
• Highly vascularized & innervated
• Function : Support skin nutritionally & structurally

6. Dermis

7. Papillary Dermis Reticular Dermis
Thinner Thicker
More superficial Deeper
Areolar connective tissue Dense irregular connective tissue.
• Contains:
1) More connective tissue cells.
2) Less collagen fibers.
3) Thin collagen fibers.
4) Thin elastic fibers.
5) More ground substance.
6) Meissner’s corpuscles (touch).
• Contains:
1) Less connective tissue cells
than the papillary layer.
2) More collagen fibers.
3) Thick collagen fibers.
4) Thick elastic fibers.
5) Pacinian corpuscles
(pressure).
6) Ruffini’s corpuscle
(stretching).

8. Hypodermis
• Loose connective tissue & fats
• Adipocytes: as storage for fats
• Functions :
– Provide thermal insulation
– Crucial energy store
– Shock absorber
– Hormone factory (steroid
hormone)

9. Appendages of the skin
There are 5 skin appendages:
1) Hair follicles
2) Sebaceous glands
3) Arrector pili muscle
4) Sweat glands
5) Nails

10. History Taking

11. History Taking.
•Patient Identification
•Chief Complaint
•History of Presenting Illness
•Past Medical/ Surgical History
•Family History
•Social/ Occupational History
•Drug and Diet history

12. The history should aim to elicit the following points:
• Time course of the skin condition
• Distribution of lesions
• Symptoms (e.g. itch or pain)
• Family history (especially of atopy and psoriasis)
• Social and Occupational History.
• Drug/allergy history
• Past medical history(childhood eczema,DM)
• Provoking factors (e.g. sunlight or diet)
• Previous skin treatments.
• Impairment of life quality?

13. PHYSICAL EXAMINATION.
1. Inspection.
-Ask patient to undress.
-Comment on:
Distribution- isolated, localized, regional, generalize,
symmetric, exposed area, site of pressure, dermatomes, random,
Blaschko's lines.
Character- redness (erythema), scaling, crusting,
exudate,excoriations, blisters,
erosions,pustules,papules,monomorphic, polymorphic.
Shape of the lesions-small, large, annular (ring shaped),
linear.
Margin- Well defined? Ill defined?

16. 2. Palpation.
– Temperature
– Consistency
– Tenderness
– Depth (dermal or subcutaneous)
– Mobility