Table of contents
- 1. Skin Structure
- 2. Morphology
- 2.1. Macule/Patch
- 2.2. Papule & Plaque
- 2.3. Pustule & Vesicle/Bulla
- 3. Seconary Morphology
- 4. P-SCALDA
- 4.1. Fitzpatric Skin Type
- 4.2. Size
- 4.3. Colour of Lesions
- 4.4. Arrangement of lesions
- 5. Distribution
- 6. Always Remember
- 7. Morphological Groups
- 7.1. Papulosquamous
- 7.2. Dermatitic
- 7.3. Morbiliform
- 7.4. Vesiculobullous
- 7.5. Acneiform or Follicular
- 7.6. Urticarial
Skin Structure
- 5 main layers
- Stratum Corneum (Keratin Layer)
- Stratum Lucidum
- Stratum Granulosum
- Stratum Spinosum
- Stratum basale
- 4 types of cells
- Keratinocytes (epidermal cells)
- Melanocytes
- Langerhan cells
- Merkel Cells
Morphology
| <1cm | >1cm |
| Macule | Patch |
| Papule | Plaque |
| Nodule | Tumour |
| Vesicle | Bulla |
| Pustule | Abscess |
| Wheal(hive) | Wheal (hive) |
Macule/Patch
- Flat
- <1cm in diameter (macule), >1cm (patch)
- Differs by color
Papule & Plaque
- Elevated above level of skin
- <1cm (papule), >1cm (plaque)
-
Papule Plaque 
Pustule & Vesicle/Bulla
- Pustule:
- Elevated above skin level
- Contains purulent fluid (white, yellow, or greenish-yellow)
- Vesicle
- Elevated above skin level
- Contains fluid (blood, serum lymph)
- <1cm in diameter
- Bulla
- Elevated above skin level
- Contains fluid (blood, serum, lymph)
- >1cm in diameter
- Elevated above skin level
Seconary Morphology
| Erosion
|  |
| Ulcer
|  |
| Scar
|  |
| Scale
| |
| Crust
of serum/blood/pus |  |
| Fissure
|  |
| Excoriation
|  |
| Lichenification
|  |
| Atrophy
loss of skin markings |  |
P-SCALDA
Example:
Fitzpatric Skin Type
Size
- i.e. "numerous lesions ranging 2-4mm in diameter"
Colour of Lesions
- Example colors:
- Red
- Erythematous = Red & blanchable
- Purple = Violaceous
- White = Hypopigmented
- Very White = Depigmented
- Brown = Hyperpigmented
- E.g. "There are numerous erythematous lesions ranging from 2-4mm in diameter"
Arrangement of lesions
- Types:
- Solitary
- Linear
- Annular
- Serpiginous
- Reticular
- Grouped
- Herpetiform
- Zosteriform
- Guttate
- Targetoid
- Satellite
- Scattered
- Disseminated
- Generalized
| Solitary (E.g. BCC) |  |
| Linear (E.g. Lichen striatus, contact dermatitis - poison ivy) |  |
| Annular/Arciform (Ring shaped, central clearing, Tinea corporis) |  |
| Reticular (Livedo reticularis) |  |
| Serpiginous (E.g. Cutaneous larva migrans) |  |
| Grouped (Bed bugs) |  |
| Herpetiform (Herpes Simplex) |  |
| Zosteriform (Herpes Zoster - Shingles) |  |
| Guttate (Raindrop, scattered/discrete, guttate psoriasis) |  |
| Targetoid (concentric ring, erythema multiforme) |  |
| Satellite (Candida infection) |  |
| Scattered (normal skin in between - Guttate psoriasis) Disseminated (Coering large area - back) Generalized (covering most body surface - SJS) |  |
- E.g. There were numerous erythematous scattered "lesions" ranging from 2-4mm in diameter
Distribution
- Anatomical Site
- Localized vs. Generalized
- Symmetric vs. Asymmetric
- Sun-exposed
- Intertriginous - Body folds
- Follicular - Surrounding hair follicles
- Site of trauma - Koebnerization or isomorphic response
Always Remember
- Check:
- Scalp & Hair
- Nails
- Mucous Membranes
- Intertriginous Sites
Morphological Groups
Papulosquamous
- Red, well demarcated and scaly
Dermatitic
- Red, Not well demarcated, usually scaly.
- Often see excoriations.
- Acutely can see vesicles
Morbiliform
- Blanchable erythematous macules and papules
- AKA "maculopapular".
Vesiculobullous
- Vesicles, bulla, erosions, crust +/- ulceration
Acneiform or Follicular
- Lesions around hair follicles
Urticarial
- Blanchable papules and plaques
Comments