Dermatology Flashcards
1
Q
DCM for describing a rash
A
Distribution: E.g. skin folds, flexural, size
Configuration: Linear, annular (ring), discoid (coin like), cluster
Morphology: Purpuric, vesicular, maculopapular
2
Q
Macula
Papule
Vesicle
A
Flat (non-palpable) area of altered colour <0.5cm e.g. freckle
Solid raised lesion
Raised, clear, fluid filled lesion
3
Q
6 main skin functions
A
Protection against environment
Temperature regulation
Sensation
Vitamin D synthesis
Immunosurveillance
Stop fluid loss
4
Q
Skin layers
A
Epidermis
Dermis
Subcut tissue
5
Q
Main cell types of Epidermis
A
Karatinocytes
- Produce protective layer (keratin)
Langerhan’s cells
- Present antigens activate T-cells
Melanocytes
- Make melanin protect nuclei from UV DNA damage
Merkel cells
- Special sensation nerve endings
6
Q
Epidermal layers
A
Come Get Sun Burned (from superficial to deep)
- Stratum Corneum (Horny- keratin layer)
- Stratum Granulosum
- Spinosum (prickle - differentiating cells)
- Basale (actively dividing cells
7
Q
What is contained in Dermis
A
Mainly made of collagen, elastin, glycosaminoglycans
Immune cells, nerve cells, skin appendages, lymphatics. blood vessels
8
Q
Types of skin appendages
A
Hair
Nails
Sebaceous glands
Sweat glands
9
Q
Hair types and made of
A
3 types (lanugo - fine, vellus - body, terminal - coarse i.e. scalp, eyelash), made of modified keratin, divided into shaft (keratinised tube) and bulb (actively dividing cells and melanocytes)
10
Q
Sebaceous gland function
A
Produce sebum via hair follicles (lubricates and waterproofs)
Stimulated by conversion of androgens to dihydrotestosterone
11
Q
Sweat glands function and type
A
Regulate temperature, innervated by SNS.
2 types eccrine (skin) and apocrine (axilla, anus, genitalia - only function from puberty, bacteria - body odour).
12
Q
4 stages of wound healing
A
Haemostasis: Vasoconstriction and Pt aggregation (clot formation)
Inflammation: Vasodilation, migration neutrophil and macrophage (key) to phagocytose debris
Proliferation: Granulaiton tissue (from fibroblasts), angiogenesis, re-epithelialisation
Remodelling: Collagen fibre reorganisation, scar maturation
13
Q
Emoillients:
- Use
- Directions
- SE
- Examples
A
To rehydrate skin, re-establish surface lipid layer
Use Liberally
SE: Irritant (rash)
Diprobase (cream)
Double base
Dermol (antibacterial)
14
Q
Topical corticosteroid strengths
1) mild
2) moderate
3) potent
4) V.potent
A
1) Hydrocortisone
2) Eumovate
3) Betnovate
4) Dermovate
15
Q
Topical corticosteroid Indications
A
Anti-inflam and Anti-prolif
allergic/immune conditions, blistering, inflammatory skin conditions, CTDs, vaculitis
16
Q
Topical corticosteroid SE
- local
- systemic
A
Skin atrophy, telangiectasia, striae, exacerbation skin conditions: acne, perioral dermatitis
HTN, Immunosuppression, Psychosis, Diabetes, Osteoporosis, Cataracts
17
Q
Topical Abx and SE
A
Fusidic acid, mupirocin, neomycin
Local (irritation, allergy)
Systemic: GI upset, rash, anaphylaxis, candidiasis, ABX associated infections
18
Q
Oral retinoids (similar to Vit A)
- EG
- Indications
- SE
A
Isotretinoin, Acitretin
Acne, Psoriasis
Dry skin/lips/eyes, disordered LFTs, hypercholesterolaemia, Myalgia/arthralgia, Depression, Teratogenicity
19
Q
Tacrolimus and Ciclosporin
How do they work (Think T&C)
A
Immunosupressors
Inhibit Calcineurin which inhibits T-cell activation
20
Q
Azathioprine
physiology
SE
A
Immunosuppress
Inhibits enzymes required for DNA synthesis of T & B cell
SE: hepato/myelotoxicity
21
Q
Atopic eczema (atopy = IgE)
Definition
Aetiology
Distribution
A
Chronic inflammatory skin disorder. Itch, erythema, Scaly patches
genetic susceptible and env factors (hygiene hypoth) result in defect in skin barrier function and dysregulation post allergen exposure
Flexor surfaces (skin folds) Also face in infants
22
Q
Atopic eczema pathophys
A
1) defect skin barrier function
- genetic defect in barrier protein = inc desquamation = barrier defect.
- increased exposure/sensitisation to cutaneous antigens
2) immune function disorder
- Th2 response post acute phase sensitisation = IL4/5/13 over express
- Results in increased IgE and peripheral eosinophils
3) Exacerbating factors: infection, soap (inc pH), dust, sweat, heat, stress
23
Q
Atopic eczema Dx
A
Itchy skin + 3 of:
History of flexural involvement
Visible flexural dermatitis
Personal history asthma, hayfever (or family if <4)
Generally dry skin in last year
Onset at <2
24
Q
Complications of Atopic eczema
A
Bacterial superinfection (S.aureus)
Eczema herpeticum (HSV)- emergency
25
Other tests to consider in Atopic eczema
Serum IgE
Allergy testing (skin prick or RAST - radio allergen blood test to see specific IgE and determine allergen)
26
Steps in Atopic Eczema Tx
1) emollient, avoid trigger
2) Low/mild topical steroid ( Hydrocortisone, Euvate)
3) Mild/high potency
4) Systemic therapy or UV therapy
27
Atopic aczema presents with
RFs: atopy, family history eczema
Pruritus
Xerosis (dry skin) - hallmark
Erythematous scaly patches @ flexor surfaces
Acute lesions
(Vesicles and weeping)
Consequences of chronic scratching/rubbing
(Lichenification and excoriation)
Hypopigmentation
28
Contact dermatitis
- Hx and pres
- Types
- Diagnosis
- Tx
History of contact with irritants / Occupational exposure
Localised burning, stinging, itching, blistering, redness, swelling at area of contact
Irritant - direct toxicity without prior sensitisation
Allergic - delayed hypersensitivity (history of atopy)
History/Patch testing to help identify agent
Irritant: emollients/topical corticosteroids + alergen/irritant avoidance (gloves)
29
Seborrhoeic dermatitis
- what
- flares
- Tx
Itchy, erythematous patches on chest, nasolabial folds, scalp
Flares with stress, fungal infection
corticosteroids ± anti fungal (non-scalp)
30
Psoriasis
- Definition
- Characteristics
- Other features
Inflammatory disease due to hyperproliferation of keratinocytes and inflammatory cell infiltrate
Extensive erythematous, well-circumscribed, scaly plaques at extensor surfaces and scalp ( can be seen following abrasion)
50% nail changes (pitting), 10% arthritis (symmetrical poly, asymmetrical oligo)
31
Psoriasis
- Definition
- Aetiology
hypreproliferation of keratinocytes with increase basal proliferation and migration to corner
Complex interaction of genetics (THfa, FH) and env (triggers: beta block, trauma, stress), infection (guttate normally follows strep pharyngitis
32
Koebner Phenomenon
New Psoriatic skin lesions on areas of cutaneous injury in otherwise healthy skin
33
Types of psoriatic rashes
ALL ARE ITCHY
Plaque: most common (80-905), silver scaling and bleed on removal
Guttate: raindrop shaped on trunk, arms and legs. post strep tonsillitis
Seborrhoeic: nasolabial, retroauricular
Palmar, plantar
Flexural
34
Psoriasis therapies (cant be cured so manage)
- General
- Topical
- Oral
- Biological
- Photo
Educate, avoid precipitants (drugs, stress, alcohol),
Emollients, Vit D analogues, topical corticosteroids.
MTX (IM weekly) + folic acid
Acitretin (retinoid - regulate epithelial cell growth)
Anti-TNF: Adalimumab, etanercept, infliximab
35
Psoriasis 1st line
- Mild plaque
- Mod/sev plaque
- Guttate
Topical corticosteroid ± Vit D analogue
Phototherapy or MTX or Oral Retinoid or Biologic
Phototherapy
36
Acne Vulgaris
- Def
- Who
- Cause (typically)
- Other cause
Inflammatory disease of pilosebaceous follicles
80% teens
Hormonal: excess androgens inc sebum prod, hypercornification = comedone formation, bacterial colonisation causes inflammatory reaction
PCOS, Cushing's, Steroid use, Puberty
37
Acne Vulgaris Presentation
Open (blackhead) and closed (white) comedones
Papules nodules and cysts if inflammatory (mod/sev)
On face, upper back, chest.
Depression, low confidence
38
Acne complications
Hyperpigmentation, scarring, deformity, psychological
39
Therapies for Acne Vulgaris
Topical (for mild)
- Salicylic acid - thins skin
- Retinoids - isotretinoin (Vit A derivative - modulates epithelial prolif)
Oral therapy (mod/sev)
- Topical retinoid + oral abx (doxy, tetracycline)
- antiandrogens (female) COCP
- Oral retinoids (Isotretinoin - has SE: Depression, LFT disorder, dry skin, teratogen)
40
Types of skin cancer
Melonoma (10%)
Non-melanoma (90%)
- BCC (70%) tumour of hair follicle, METs rare, low recurrence)
-SCC (20%) keratinocyte, METs common an 20% recurrence
Pre-malig = Actinic Keratosis, In-situ = Bowen's
41
SCC Def
Locally invasive malignant tumour of epidermal keratinocytes and its appendages. Potential to metastasise.
42
SCC RF
```
UV
Premalig lesions (AK, Bowen's)
Chronic inflam (leg ulcer)
Immunosuppression
Previous SCC
```
43
SCC Pres
Keratotic (scaly, crusty)
Ill-defined nodule
Ulceration, bleeding
Invasive disease: Lymphadenopathy, Neural (e.g. CNVII) invasion symptoms
44
SCC spread
Quick growing, Local mets/spread to Local LN
45
SCC investigations
Biopsy
- Keratonicyte atypia
- For invasive = penetrate to dermis
CT/MRI
- For mets
- Regional LNs , lung, liver, brain, bone
46
SCC Tx
- In situ
- Invasive
- Mets
- Follow up
Topical chemo (Efudix - 5FU)
Wide local excision (4mm) or Mohs (ill defined/recurrent)
Excision + radiotherapy
3-6 month follow up, sun avoidance
47
BCC
- Other name
- Def
- RF
Rodent ulcer
slow growing, locally invasive malignant tumour arising from hair follicle
UV exposure, sunburn as child, Type 1 skin, White, age
48
Typical appearance BCC
- Nodular
- Superficial
- Morphoeic
Head & neck. small nodule, surface telangiectasia, pearly rolled eye, ulcerated centre
Trunk/shoulder, erythematous plaque
Resembles melanoma, more aggressive, poorly defined borders (Mohs surgery)
49
Investigtion BCC
Excisions biopsy
50
Treatment BCC
surgical excision and histology
higher risk (morphoeic) get Mohs
Radiotherapy sometimes given
Low risk = Efudix
51
Describing a pigmented lesion
ABCDE
```
Asymmetry
Border
Colour
Diameter
EVOLUTION
```
52
Malignant melanoma, why important?
Melanoma is the most common cause of death from skin cancer. Metastasis can occur early
53
Malignant melanoma definition
Invasive malignant tumour of epidermal melanocytes (in basal layer)
54
Non-cancerous melanocytes growth
Naevi (mole)
55
Malignant melanoma RFs
Excess UV, type I skin (burns), atypical moles, FH, immunosuppression
56
Types of Malignant melanoma
```
Superficial spreading (70%)
- grow lateral before going deep
```
Nodular (20%)
- Aggressive, rapidly growing
Lentigo maligna
Acral - palms, soles, nails. not related to UV
57
Malignant melanoma investigations
Dermatoscope (ABCDE)
Biopsy: abnormal melanocytes proliferation in epidermis/dermis (invasive if in dermis)
Assess mets: sentinel LN biopsy, CXR & Liver USS, CT chest/abdo/pelvis
58
Breslow's thickness
Depth of invasion, determines margin of excision
1) thin: 1mm = 1cm margin
2) Intemediate: 1-4mm = 2cm margin
3) Thick: over 4mm 2-3cm margin
59
Malignant melanoma Treatment
Wide local excision and SLN biopsy if intermediate/thick
Im mets: Lymphadenectomy, radio, chemo (pembrolizumab - anti programmed death receptor
60
Impetigo:
- Who
- Appearance
- When
- Organism
- Tx
Highly contagious, common in children
Goldencrust/vesicles/bullae (in bullous impetigo)
Post trauma / skin breaks e.g. eczema
Staph aureus
Abx:
- Topical fusidic acid (narrow spect abx against Staph aureus)
- Oral Fluclox
61
Herpes simplex
- types
- Tx
Type 1 = oral herpes
Type 2 = Genital herpes
Aciclovir oral ± topical
62
Cellulitis
- Def
- RF
- Organism
Spreading of bacterial infection in deep sub cut layers with overlying skin inflammation (erythema, oedema, warm, tender)
Immunosuppression, wounds, ulcers, poor hygiene, poor vascularisation (e.g. DM)
Staph aureus, Strep pyogenes/other strep
63
Ddx cellulitis
```
Thrombophlebitis
DVT
Gout
Necrotising fasciitis
Abscess
```
64
Cellulitis investigations
FBC (raised WCC), Blood culture, culture purulent foci (s.aureus), If orbital cellulitis CT/MRI to check abscess)
65
Complications in cellulitis
Local tissue damage
Sepsis
Orbital cellulitis: blindness, abscess formation - intracranial
66
Abx for cellulitis
General:
-Flucloxacillin (oral)
Severe:
- MRSA cover: vancomycin/tazocin
Orbital:
- 3rd gen cephalosporin + MRSA cover
- IV Ceftriaxone +Vancomycin
Bite related:
- IV co-amoxiclav (Pasteurella cover)
67
Scalded skin syndrome
Condition seen in children due to epidermolytic endotoxin from Staph aureus
Develops over hours
worse in face, neck, axilla, groin
painful blistering lesions, fever
68
Scalded skin syndrome Tx
Analgesia
Antibiotics (IV the oral fluclox) fluids (beware dehydration)
Recover 5-7 days
69
Fungal infections
Common and mild
Usually superficial and itchy
70
Tinea capitis
Scalp ringworm: Patches broken hair, scaling and inflammation
71
Dermal candida
White plaques on mucosal areas (mouth, genitalia), erythema with satellite lesions in flexures
Itchy
72
Management of fungal infections
- Diagnosis
- Treatment
Skin scraping, swabs, hair/nail clipping
Topical anti fungal (terbinafine cream)
Oral (itraconazole, fluconazole)
73
Verrucae cause mimics Tx
HPV6-11
SCC
Cryotherapy, silver nitrate, debridement
74
Scabies
| - Cause, transmission, where seen
Infection with mites, transmission via skin to skin contact. Often seen in overcrowded living conditions
75
Scabies
- Pres
- Diagnosis
Pruritus, erythematous papules, linear burrows in interdigital web space
Microscopic visualisation of mites, eggs in skin scraping
76
Scabies
| - Tx protocol
```
Treat the whole family + wash clothes >60 degrees
Topical permethrin (5%) + antihistamines: apply from neck down and wash after 8 hours
```
77
Ulcers
- Def
- Cause
Break in epithelial surface
Venous 80%
Arterial 20%
78
Venous ulcers pathophys
Venous insufficiency
Incompetent valves in veins of lower leg
Blood is squeezed into superficial veins rather than to heart = dilation (varicosities) and raised pressure
Raised pressure causes oedema and poor oxygenation of surrounding skin
Ulceration
79
Signs of venous insufficiency
Ankle swelling, hyperpigmentation (haemosiderin), heavy legs, dry/scaly skin, telangiectasias, varicose veins, itching
80
Venous ulcers RF
Age, family history, smoking, DVT, orthostatic occupation (sitting)
81
Venous ulcers site and appearance
Medial/Lateral malleolus
Between knee and ankle
Large, shallow, painless, irregular boded, moist granulating base
82
Venous ulcers investigations
ABPI using doppler for pulses (exclude arterial)
Swabs & microbiology
Biopsy if fail to heal in 12 weeks
83
Venous ulcers Treatment
Graduated compression (max pressure at ankle, decreases going up)
Debride/Clean
Dression: hydrocolloid
Abx if cellulitis
84
Arterial ulcers
- Cause
- Pres
- site
- Appearance
Atherosclerosis/tissue hypoxia
CV RFs (smoking, DM), absent pulses, 6Ps (pale, pulseless, perishingly cold, paresthesia, pain, paralysis)
More distal: dorm of foot/toes
Painful, great/granulating base, no bleeding on decried, punched out, cold/shiny/hairless skin surrounding
85
Arterial ulcers investigation and treatment
ABPI: BP cuff on lower calf, doppler probe dorsals pedis
- less than 0.0 = peripheral arterial disease
Vasc surgery and analgesia may be needed
DO NOT USE COMPRESSION!
86
Neuropathic ulcers:
- Who
- Site
- Appearance
- Tx
Diabetics (commonest)
Under callouses, over pressure points (plantar aspect 1st - 5th metatarsaophalangeal joint)
Punched out, deep sinus, brisk to bleed, painless, necrotic base
Diabetic foot management
87
Urticaria
- Pathophys & Pres
- Tx
Histamine (from skin mast cells - antigen IgE cross link) and other cytokine (PG, Leukotrienes) = inc permeability of Blood vessels
Exposure to allergen/toxin
Itchy Wheals (swelling and erythema)
swelling of superficial dermisfor 30m-24hr)
Antihistamines
88
Angioedema
- Pres
- Description
- Complications
Swelling of tongue, eyelids, lips
Dermis/subcut swelling. Lasts up to 24 hrs
Asphyxia (due to suffocation), cardiac arrest, death
89
Anaphylaxis triad of presentation
1) Bronchospasm (stridor = severe)
2) Facial, Laryngeal swelling
3) Hypotension
90
Anaphylaxis common causes
Food
Nuts, sesame seeds, shellfish, dairy
Drugs
Mainly penicillin
Contrast media, NSAIDs, morphine, ACE-I
Contact
Latex
Bites
Insect
Autoimmune
91
Anaphylaxis acute management
IM adrenaline 500 micrograms (0.5ml 1 in 1000 - mid anterolateral thigh)
Airway protection
IV antihistamines (chlorphenamine/dipenhydramine = 2nd generation)
IV corticosteroids (hydrocortisone)
Trigger identification + avoidance
92
Erythema nodosum
- What is it
- Causes
- Tx
Erythematous lumps on shins from inflammation of subcut fat
Inflam bowel (UC/CD)
TB
Strep throat
Sarcoidosis (Seen with mediastinal LNs)
Treat cause, if pyoderma gangrenous = prednisolone
93
Stevens-Johnson syndrome
Vs
Toxic epidermal necrolysis
Mucocutaneous necrosis covering less than 10%. 5% mortality
TEN is over 30%. has a 25% mortality
Both involve at least two mucosal sites and occur following Anticovulsants, ABx, NSAIDs
94
Stevens-Johnson syndrome and toxic epidermal necrolysis
Pathophys
Diagnosis
Detachement of epidermis from dermis
Skin biopsy and histopathology (necrosis and inflammatory cells)
95
Stevens-Johnson syndrome and toxic epidermal necrolysis
| Tx
Call for helpQ
Withdraw causative agent
Dressing, topical antibacterial and emollients
IV fluids
Analgesia
96
Stevens-Johnson syndrome and toxic epidermal necrolysis
| Complications
Dehydration, infection and sepsis, multi-organ failure
97
Necrotising fasciitis
- Definition
- Organism commonly
- RF
- Presentation
infection of deep fascia - rapidly spreading
Group A strep (pyogenes)
Abdo surgery, DM, Malig
50% in healthy individuals
SEVERE PAIN, erythematous necrotic skin, systemically unwell (fever, tachycardia), subcutaneous emphysema
98
Necrotising fasciitis management
Rapid surgical debridement and haemodynamic support
Empirical broad spectrum ABx
- Vancomycin and Tazocin
99
Rosacea
- What is it
- Tx
Skin flushing and erythema
Topical antibiotic/anti-inflam ± oral Abx
Metronidazole topical
Doxy oral
100
Seborrhoeic keratosis
- Visual desc
- Cause
- Tx
Common benign skin lesions (look stuck on) due to UV sun damage
Tx: steroids if itchy, Cryotherapy if flat
101
Lichen Planes
- inflammatory disease with itchy affecting skin + genitals
Tx: topical corticosteroids
102
Systemic causes of pruritus
Renal: chronic renal failure (urea mediated)
Cholestatic (Bile salt mediated)
Haematological (Polycythemia vera)
Endocrine (Hypothyroid, DM)
Malignant: Hodgkin lymphoma (Bradykinin), Carcinoid (serotonin)
103
Vasulitic skin changes
- Small vessels
- Medium vessels
Purpura, petechiae, ulcers
Nodules, Livedo reticularis (lace/purple discolourations on skin)
104
Alopecia areata
- Cause
- Pres
- Tx
- Prog
Autoimmune (t-cell) target hair follicles
Patchy hair loss, exclamation mark hairs
Topical corticosteroid and cosmetic camouflage
Relapses occur. spontaneous regrowth in 2 years
105
Androgen alopecia
Male pattern baldness
Androgen mediated follicular miniaturisation (seen in women with PCOS and onset of menopause, TFT as can be seen in hypothyroid)
106
Dermatitis herpetiformis
- Assoc with
- Pathophys
- Pres
- Tx
Coeliac disease
IgA deposits in the dermis
Itchy vesicular rash on extensors and buttocks
Low gluten diet
107
Severe, widespread rash including mucosa assoc with recent infection ...
Stevens-Johnson syndrome
108
Acanthosis Nigricans Causes
Diabetes mellitus
| Gastric adenocarcinoma
109
Red ulcerating lump associated with IBD
Pyoderma gangrenosum
110
One trunk patch and then several round erythematous scaly patches follow
Pityriasis Rosea
111
Vitiligo assoc diseases
Autoimmune
(Tx with topical steroids- reverse if early, sunblock, camouflage, tacrolimus)
Also get koebner phenomenon here
112
What heart medication can worsen psoriasis
Beta blockers
113
Premalignant sun damage
Actinic Keratosis
114
4 D's of Pellagra (Caused by Vit B3 def e.g. due to Isoniazid)
Diarrhoea
Dermatitis
Dementia
Death
115
White patches in a smoker
Leukoplakia
| Risk of malignant transformation
