1. INTRODUCTION TO DERMATOLOGY

2. Important functions of the skin
Dermatology deals with disorders of skin, hair, nails, and mucous membranes.
Important functions of the skin
Protection against external injury
Fluid balance
Temperature organ
Synthesis of Vit D
Part of immune system (e.g. langerhan’s cell)
Cosmetic function.

3. Dermatological disorder = 10% -15% of primary care consultations
Skin is the largest organ in human body
Dermatological diseases can cause social and psychological problems, also it may affect ability to work (e.g.. Chronic hand dermatitis.)
Skin is the gate of the body(might reflect systemic disease).

4. Structure of skin Epidermis
Basement membrane (dermoepidermal junction)
Dermis
Subcutaneous fat
Epidermis: Four layers (from outside – inside)
Cornified layer
Granular layer
Spinous layer
Basal layer
Dermis contains:
Collagen fibers
Elastic fibers
Ground substances
Blood vessels
Nerves.

5. Skin appendages:
Hair follicle
Sebaceous gland
Arrector pili muscle
Eccrine sweat gland
Apocrine sweat glands
Nail

13. Dermatological History
age, sex
Chief complaint : + duration
itching
burning
pain
History of present illness
When and how started?
Mild, moderate or severe?
Aggravating or reliving factors?
Any other symptoms
Review of systems
Past medical history
Drug history

14. Examination: Occupation Hobbies Travel Family history
3 corners to make useful skin exam
Morphology (shape of the lesion)
Configuration (arrangement of lesions)
Distribution (Which body site)
Morphology:
1º skin lesions : unmodified lesions
2º skin lesion: modified by scratching or infection

15. Primary Lesions Secondary lesions
Macule Crust
Papule Erosion
Plaque Scale
Nodule Ulceration
Cyst Excoriation
Wheal Scar
Vesicle Atrophy
Bulla Fissure
Purpura Necrosis
Burrow Lichenification
Telangectasia

16. Primary skin lesions

17. Macule & patch
A macule is a circumscribed flat alteration in the colour of the skin which is less than 1 cm in diameter.
Various colors depending on the cause
A patch is a flat lesion greater than 1 cm in diameter (i.e. a large macule).

18. Papule
A papule is a circumscribed palpable elevation of the skin less than 1 cm in diameter
Dermal(drug eruption, lipid deposits), epidermal (warts, molluscum), or both (lichen planus)

19. Nodule Palpable solid deep lesion (depth> diameter) - Epidermal

20. Plaque A slightly raised lesion greater than 1 cm in diameter
Papules confluence (psoriasis)
Patch thickening (mycosis fungoides)

21. Vesicle
A raised lesion less than 0.5 cm in diameter containing clear fluid

22. Bulla
A vesicle that is greater than 0.5 cm in diameter is known as a bulla.

23. Pustule
A pustule is a raised lesion less than 0.5 cm in diameter containing yellow fluid, which may be sterile as in acne or pustular psoriasis, or infected.

24. Wheal
A wheal is a transient, itchy, pink or red swelling of the skin, often with central pallor.

25. Cyst:
palpable soft sac containing fluid.
- Epidermal
- Dermal

26. Telangiectasia
Dilatation of capillaries gives rise to this skin condition.

27. Secondary skin lesions

28. Crust
A crust is a dried exudate, which may have been serous, purulent or haemorrhagic.

29. Excoriation
A haemorrhagic excavation of the skin resulting from scratching.

30. Lichenification
Thickening of the skin with exaggeration of the skin creases.

31. Scar
The final stage of healing of a destructive process (disease or injury) that has involved the deeper dermis results in a white, smooth, firm, shiny lesion.
Atrophic, or hypertrophic

32. Scale A scale is a flat plate (lamella) or flake of stratum corneum.
The epidermis is replaced every 28 days
Fine (eczema) / thick (psoriasis)
No scaling in dermal pathologies

33. Poikiloderma
This refers to an appearance of pigmentation, atrophy and telangiectasia

34. Necrosis
Death, or necrosis, of skin tissue is usually black in colour.

35. Erosion A partial break in the epidermis is known as an erosion
It heals without scarring unless secondary infection occurs.
Commonly following a blister

36. Ulcer An ulcer is a full-thickness loss of the epidermis
Heals with scarring

37. FISSURE
a linear cleavages or cracks in the skin.

38. Atrophy Thinning and transparency of the skin
Caused by diminution of the epidermis, the dermis, or both
Wrinkling and translucency

39. Sclerosis
A circumscribed or diffuse hardening or induration of the skin
A result of dermal or subcutaneous edema, cellular infiltration, or collagen proliferation

40. Primary Lesions
Macule: Flat circumscribed area of change in skin color
Papule: small circumscribed elevation of the skin
Nodule:Solid, circumscribed elevation of the skin whose greater part is beneath skin surface (felt more than seen)
Plaque: flat topped palpable lesion (gathering of papules)
Vesicle: collection of clear fluid (<5mm in diameter)
Bulla: like vesicle, but > 5 mm
Pustule: Collection of Pus

41. Primary Lesions
* Wheal: Transient, slightly raised lesion with pale center and pink margin.Seen in urticaria.
* Purpura:Visible collection of blood under the skin e.g. Vasculitis
* Telangectasia: Dilated capillaries visible on skin surface
* Burrow: Tunnel in the skin (e.g. Scabies)

42. Secondary lesions Crust: Dried serum (or exudate)
Scale:Thickened, loose, readily detached fragment of
cornified layer
Excoration: Shallow linear abrasion caused by
scratching.
Erosion:Loss of epidermis (heals without scarring)
Ulcer: loss of epidermis and dermis (heals with
scarring)
Fissure : linear crack in the skin
Scar: Permanent lesion due to abnormal formation of
connective tissue following injury.

43. Secondary lesions
Atrophy: A-Superficial: thining of skin with visible blood vessels
B-Deep : depression of skin surface
Lichenification: thickened skin with
accentuated skin markings
Sclerosis: induration of skin

48. Distribution Predilection for specific body sites
*Psoriasis: Extensors(elbows and knees)
Scalp
*Acne:Face
Upper chest, Upper back
*Photosensitive eruption: Mainly face, forearms & V-Chest (with sparing of photoprotected areas e.g. upper eyelids, retro-auricular an sub- mental)

50. Colour in Dermatology Red:Vascular lesions e.g. port wine stain
also, inflammatory disorders like psoriasis
Blue: Blue nevus
Mongolian spot
Yellow: Xanthoma
White: Vitiligo
Black: Melanocytic nevus & melanoma
Purple or (Violaceous) : Lichen planus

53. Some important signs in Dermatology
*Auspitz sign: When you remove a scale from psoriasis lesion  tiny bleeding points (due to suprapapillary thinning).
Nikolsky sign: When you rub normal skin beside blister  induction of new blister .Seen in pemphigus vulgaris and toxic epidermal necrolysis(TEN).

54. Nikolsky sign

55. Dermatographism: When you stroke the normal skin  edema and erythema (you can write on skin!) .Seen in physical urticaria
Kobener Phenomenon: Induction of new skin lesions on previously normal appearing skin by truma e.g. in psoriasis, wart, lichen planus
Button-hole sign: In neurofirbroma, if you try to push it  it goes inside the skin

57. Additional skin examination:
~Wood’s Lamp: Produces long wave ultraviolet light(UVA). e.g.
Vitiligo  milky white
Tinea Versicolor  golden
Tinea Capitis (caused by microsporum)  yellow green
Erytherasma  coral red
~Diascopy:you press with a glass slide .
If there is red lesion and the redness dose not go away by this pressure  this means extravasated blood i.e.purpura
~Dermatoscopy: Helpful to differentiate benign from malignant pigmented lesions.

59. Investigations: *KOH and fungal culture
Scrap skin scales  put over glass slide
Add KOH 10% -- warm gently
See under microscope
You may see hyphae and/ or spores
*Gram stain and bacterial culture

60. Investigations:
Tzank smear: Scrap base of vesicle smear it on microscopic slide  add fixative  add Giemsa stain.
Examine under microscope for
1.Detached epidermal cells (acantholytic cells) in pemphigus vulgaris
2.Multinucleated giant cells in herpes simplex, zoster or varicella
Viral culture

61. important in immunobullous disorder 1. Direct : use pt’s skin
Skin biopsy : Under local anasthesia, different types: Punch
Shave
Excisional
Incisional
Immunofloursence :
important in immunobullous disorder
1. Direct : use pt’s skin
2. Indirect: use pt’s Serum
Prick test
Patch test

68. Treatment: Topical corticosteroids Mechanism of action
1. Anti-inflammatory
2. Anti-proliferative
3. Vascoconstrive
4. Immunosuppressive

69. Topical steroids (cont’d)
7 Categories, according to strength .
Category one is superpotent (used only on chronic cases or resistant disorder on thick skin) .Not used on face or in children. e.g. Dermovate (clobetasol propianate).
Category seven is very mild: can be used safely in children or over face, also for longer periods of treatment
See tables. 1

70. Group 1 (Most Potent) Group 2 Group 3 Group 4 Group 5 Group 6 Group 7
Clobetasol propionate ointment 0.05% (Temovate,Dermovate)
Clobetasol propionate cream 0.05% (Temovate, Dermovate)
Betamethasone dipropionate ointment 0.05% (Diprolene)
Group 2
Betamethasone dipropionate cream 0.05% (Diprolene)
Mometasone furoate ointment 0.1% (Elocom)
Group 3
Fluticasone propionate 0.005% (Cutivate)
Group 4
Mometasone furoate cream 0.1% (Elocom)
Triamcinolone acetonide ointment 0.1% (Kenalog)
Hydrocortisone valerate cream 0.2% (Westcort)
Hydrocortisone butyrate ointment 0.1%(Locoid)
Group 5
Fluticasone propionate cream 0.05% (Cutivate)
Triamcinolone acetonide 0.1% (Kenalog)
Hydrocortisone butyrate cream 0.1%(Locoid)
Group 6
Alclometasone dipropionate 0.05% ointment (Perderm)
Alclometasone dipropionate 0.05% cream (Perderm)
Group 7
Topical preparations with hydrocortisone acetate 1%

71. Topical steroids (cont’d)
Various formulations:
Ointment, cream ,gel, solution, lotion
Side effects (if used for long period and at inappropriate site):
Atrophy , Acne
Telangectasia, Hypertrichosis
Folliculitis, Hypopigmentation
If large amounts  systemic absorption .
But if you use it with appropriate strenght and amount in appropriate site; these S/E are unlikely to happen

73. Topical retinoids (vit.A derivatives)
Topical Antifungal :
Miconazole
Terbinafine
Clotrimazole
Ketoconazole etc….
Topical Antibiotids:
Fusidic acid
Mupirocin
Erytheromycin
Clindamycin etc…
Topical retinoids (vit.A derivatives)
Commonly used In Acne
e.g. Treitinoin(Retin A)
Adapalene(Differin)

74. *Topical vit. D analogues
calcipotriene (daivonex).Used in psoriasis
Main S/E :hypercalcaemia
if more than 90 grams used per week (for adult)
*Topical chemotherapy:e.g. 5 -flurouracial, used for actinic keratosis (premalignant skin lesions)
*Topical immunomodulator :e.g.
-Imiquimod(Aldara )used for genital warts
*Topical immunosuppersives: e.g.
-Tacrolimus used for Atopic Dermatitis

75. Intralesional treatment
*IL steriods : e.g. Triamcenolone acetonide (kenalog) with different concentration according to the case
Used in many skin disease e.g.
Alopecia areata (localized vaiant)
Keloids
Licen simplex chronicus
Hemanigomas
S/E: atrophy
hypopigmentation.

76. I L chemotherapy:
*Bleomycin : for plantar warts
*Vinerstine and vinblastine: for kaposi sarcoma
IL Antiprotoza:
like Na stibogluconate used in treatment of leishmaniasis
Intramuscular injections:
*Steriods
*Pentostam (Na stibogluconate)

77. Physical methods
-Cryotherapy : e.g. Liquid Nitrogen used in treatment of warts
-Electrcautery
-Sclerotherapy for varicose viens
-Curettage

79. Oral Medications Systemic steroids:
The most commonly used is prednisolone
What are the S/E ? DM ,Wt gain
HTN
HPA axis suppersion
Osteoprosis,
Avascular necrosis
Pyschosis,Depression
etc….
How to prevents them?
Monitor BP, blood sugar
Vit. D. ,Calcium supplement

82. Oral Medications Antibiotics: Pencillins Cephalosporins Macrolides
Fluoroquinolones
Tetracyclines
Anti-TB
Anti- Leprosy

83. Oral Medications Antiviral Acyclovir Famcilovir Valacyclovir
Antifungal : e.g.
Terbinafine Griseolfulvin
Itraconazole Ketoconazole
Antiviral
Acyclovir
Famcilovir
Valacyclovir

84. Oral Medications *Immunosuppressive and antiproliferative
Azathiopurine (imuran)
Cyclosporin-A
Mycophenolate Mofetil
Cyclophosamide
Methotrexate
*Antimalaria
* Interferones
*Systemic Retinoids
e.g. Isotreitonoin, used in acne
Acitertin used in psoriasis
S/E?(elevate LFT and Lipids,also Teratogenic)

85. Oral Medications Antihistamine:for itching
-sedating(e.g.Hydroxyzine,Chlorphenarmine)
-non sedating(e.g Loratidine and Cetrizine)
Antiandrogens
Psychotropic
Colchicine
Potassium iodide
Emoillents
Sunscreen : Chemical and physical

86. Phototherapy Ultraviolet light A or B with or without psoralen
PUVA (psoralen + UVA)
New modalities:
Narrow band UVB
UVA – 1
Excimer laser(308nm)
Indications: psoriasis, vitiligo, atopic dermatitis,CTCL(cutaneous T cell lymphoma )etc…

87. Laser acronym for: Light Amplification Stimulated Emission Radiation
Harmful if accidently goes to the eye.
Does not induce cancer
Safe for pregnant ladies
Different wavelengths targeting different chromophores
Types: Vascular , Pigmentary
Resurfacing, Hair removal

90. Depth of Penetration Laser Tissue Interactions Er C02 KTP PD Ruby Alex
Nd YAG
When selecting the energy to be delivered to the target, two factors need to be considered:
1. The energy must be high enough to destroy the target, such as hair.
2. The energy must be below the level that would damage the surrounding tissue, in this case the skin. 1 9

94. Thank you