Dermatology Flashcards
Define macule and papule
Macule = small, flat lesion <5mm Papule = small, raised lesion <5mm
Define nodule and patch
Patch = diffuse flat lesion >1cm Nodule = discrete raised lesion >1cm
Define vesicle, bulla and pustule
Vesicle = small fluid filled lesion <5mm Bulla = large fluid filled lesion Pustule = pus filled blister <5mm
What type of lesions is eczema?
Where are they found?
-Papules (small raised) and vesicles (small fluid filled)
on an erythematous base
-Commonly on flexor parts (extensor on babies)
What is the diagnostic criteria for atopic eczema?
Itchy skin condition plus 3 of the following:
- History of itchiness in skin creases
- History of atopic disease (personal or familial)
- General dry skin
- Visible flexural eczema
- Onset in first 2 years of life
What genetic mutation is associated with atopic eczema?
Filaggrin
Where and how does discoid/nummular eczema present?
- Coin shaped lesions
- Commonly at wrist
What type of hypersensitivity reaction is allergic contact dermatitis?
Type IV hypersensitivity - occurs after sensitisation and re-exposure to allergen
How can you distinguish between irritant and allergic contact dermatitis?
Irritant = fast onset of burning, stinging, soreness in exposed area and resolves quickly after removal of irritant
Allergic = delayed onset of redness, itch, scaling in exposed area and other areas. Takes longer to resolve.
Which type of contact dermatitis is more commonly associated with atopic eczema?
Irritant contact dermatitis
What is dyshidrotic eczema?
-formation of small blisters on extremities (F>M)
What is neurodermatitis
-constant itchyness, worse at night/relaxation>causes leathery skin
Eczema treatment:
1st line
2nd line
3rd line
- Topical emollients (500g/week-adults) when skin is moist
- creams, lotions, ointments, soap substitutes - Topical steroids - hydrocortisone (mildest) to dermovate (most potent)
- Phototherapy or immunosuppressants (oral pred)
What are some complications of eczema?
Lichenification in adults
Staphylococcal infection
Eczema herpeticum = rapidly worsening, painful, clustered blisters and punched out erosions
How would you treat an infection of eczema?
Flucloxacillin for 14 days (erythromycin if penicillin allergic)
How does seborrhoeic dermatitis present?
Erythematous SCALING rash over NASOLABIAL FOLDS, bridge of nose, eyebrows, ears and scalp (dandruff)
What medication can you give for seborrhoeic dermatitis?
Ketoconazole = topical antifungal (inflamitory reaction to yeast (Malassezia spp))
Pathophysiology of acne vulgaris?
Increased androgens→spots→colonisation by propionibacterium Acnes
What conditions can acne vulgaris be associated with?
What drugs can acne vulgaris be associated with?
Excess androgens e.g:
- Polycystic ovarian syndrome
- Cushing’s disease
Drugs
- Steroid abuse
- Lithium
- Porgesterone (although COCP makes it better)
What type of lesions do you see in acne?
-comedones/papules (small raised)/pustules (pus filled raised)
What are the 2 forms of severe acne?
what are the difference in spots/other features?
Acne conglobata
- cycts form
- spots linked together under the skin
Acne fulimens
- bleedy, crusty, ulcerated
- SYSTEMIC FEATURES (fluctuating fever/joint pain/lose weight)
**immediate referral is indicated for both
What is the treatment of mild acne? (3 options)
What about in pregnancy?
1st line: (mild acne) TOPICAL TREATMENTS (1 then 2 of:)
- Topical retinoids e.g. adapalene +/- benzoyl peroxide (burning>kills bacteria)
- Topical antibiotic (1% clindamycin) AND benzoyl peroxide
- Azelaic acid 20%.
PREGNACY
- *retanoids are CONTRAINDICATED in PREGNANCY
- *give topical erythromycin and benzoyl peroxide instead
Side effects of retinoids?
Teratogenic - don’t give in pregnancy
Photosensitivity
Dry skin
If topical treatments haven’t worked, what else can you prescribe for acne?
What about in pregnancy?
2nd line (moderate acne): ORAL ANTIBIOTICS 3 MONTHS
- oral doxycycline/lymecycline
- ALWAYS GIVE WITH topical retinoid (if not contraindicated) or benzoyl peroxide to reduce resistance
Can give COCP as an alternative to antibiotics
Pregnancy
**cant ive doxycycline (teratogenic)>give erythromycin
When would you consider a referral to dermatology for 3rd line acne treatment?
- acne worsens on treatment
- unable to tolerate side effects
- they are starting to scar
- if they have not responded to 2 different courses of antibiotics
Refer to derm for 3rd line treatment (isotretanoin)
What are the side effects of doxycycline?
- TERATOGENIC
- teeth/nails discolouration
- crazy dreams
What is the 3rd line treatment for acne?
How does it work?
3rd line (severe acne): ISOTRETANOIN -works by reducing sebum
What are the side effects of isotretanoin?
Side effects
- TETAROGENIC (need neg test and contraception 1 month after)
- flakey dry lips and eyes (DRY EVERYWHERE)
- hyperlipideamia
- suicidal thought
What is the pathophysiology behind psoriasis?
Most common type?
- Hyperproliferation of keratinocytes
- Inflammatory autoimmune T-cell mediated
- Most common is chronic plaque psoriasis
What is Auspitz’ sign?
Bleeding on scraping of a psoriatic lesion
What is Kobner’s reaction? What conditions demonstrate this reaction?
Lesions arising following trauma to skin in otherwise health skin
- Psoriasis
- Lichen planus
- Vitiligo
What nail changes are seen in psoriasis?
- Pitting - superficial depressions in nailbed
- Onycholysis - separation of nail plate from nailbed
- Subungual hyperkeratosis - thickening of nailbed
- Oil drop discolouration
(50% will have nail changes)
What antigens is psoriatic arthritis associated with?
HLA-B27 (also ankylosing spondylitis, IBD, reactive arthritis)
HLA-DR4 (also RA and type 1 diabetes)
List the topical steroids in order of potency?
HEBDon bridge
- Hydrocortisone (mild)
- Eumovate (mod)
- Betnovate (potent)
- Dermavate (very potent)
What topical treatment can be used in psoriasis?
- Topical emollients
- Topical Vitamine D anaglogues e.g. calipotriol (reduces keratinocyte proliferaiton)
- Topical steroids (betnovate) used for flares
Which psoraisis patients can be offered 2nd/3rd line therapy?
If extensive disease (>10% body affected)
2nd line: Phototherapy
3rd line: systemic therapy
What systemic therapy is used in psoriasis?
First-line - Methotrexate
Second-line - Ciclosporin (1st line if rapid disease control in flares> need contraception)
Third-line -Acitretin
**Biologics if above hasn’t worked-mab
What triggers a relapse of psoriasis?
· Skin trauma (Koebner phenomenon) · Infection - strep, HIV (GUTTATE) · Drugs - BALI - Beta-blockers - Anti-malarials - Lithium - Indomethacin/NSAIDs · Withdrawal of steroids · Stress · Alcohol and smoking · Cold/dry weather
What disease is oral lichen planus associated with?
Hepatitis C
What is the management of eczema herpeticum?
Oral acyclovir
Oral flucloxacillin (to cover secondary bacterial infection)
Stop topical steroids
***children should be admitted for IV aciclovir
What phototherapy is used to treat psoriasis?
1st line: Narrowband UVB phototherapy
2nd line:. Psoralen + UVA (PUVA)
Side effects of ciclosporin
5 H’s
- Hypertrophy of gums
- Hypertrichosis
- Hypertension
- Hyperkalaemia
- Hyperglycaemia (diabetes)
Requires monitoring of U&Es, BP and fasting glucose
Describe a classic BCC
- Waxy
- Rolled edges
- Central depression
What are the types of BCC?
What do they look like?
Nodular
-shiney round edge/central depression/rolled edges
Superficial
-red scaley plaques
Morphic
- blend in more (ill defined edges)
- waxy
- more aggressive
Treatment of BCCs?
- Mohs micrographic surgery (good healing)
- Radiotherapy if surgery not appropriate
BCC vs SCC (appearance/growth)
BCC
- WAXY
- slow growing
- locally invasive, less likely to metastasise
SCC
- SCALEY/CRUSTY (keratotic)
- more likely to metastasise
- common post liver transplant (immunocompromised)
What are the main precursors to SCC?
- Actinic keratoses (aka solar keratosis) - 10% progress to SCC
- Bowen’s disease
- P53 supressor gene mutation
Treatment of SCC?
Surgery with 4mm boarder
How do you treat actinic keratoses?
Topical 5 fluorouracil (5FU)
What is a slow growing patch of brown skin (often resembles a freckle on face)?
Lentigo maligna (in situ melanoma)
- irregularly shaped brown macule that grows slowly
- can progress to lentigo maligna melanoma
What is a melanoma?
Where do you most often get them?
Cancer: problem with epidermal melanocytes
Women: legs Men: trunk
What is the most common type of melanoma?
Superficial spreading melanoma is most common
grows laterally→less likely to metastasise unlike nodular→grows downwards
What is the name of melanoma on the sole of foot?
What is unique about these?
Acral melanoma
- sole of foot/nail bed
- ONLY ONE NOT EFFECTED BY UV LIGHT
What is the management of melanomas?
- Biopsy and determine breslows thickness
- Wide local excision
- May need lymphadenectomy (mets to LN are common)
- Chemotherapy if metastatic
What is a Kaposi sarcoma? (how does it look)
Soft tissue tumour presents with purple cutaneous nodules
Who does kaposi sarcoma tend to affect?
Whats the treatment?
Those with HIV (or other forms of immunosuppression)
Treatment:
- Give HIV treatment (combination of antivirals)
- Reducing transplant medication
Chemo or interferon if not worked
What is the management of keloid scars?
- Silicone dressings
- If failed>steroid injections
What is a ganglion?
A ganglion cyst is a fluid-filled swelling that usually develops near a joint or tendon
Usually back of wrist
3x more women
How long do ganglions last for?
What is the management?
-Usually self limiting: Several months then usually disappear
- If pain or loss of movement:
a) aspiration
b) excision
What is a cherry hemangioma?
Campbell de Morgan spot
Benign proliferation of mature capillaries
Treatment of common warts?
Self limiting, however treat if painful/cosmetic/patient request
- Cryotherapy every 2 weeks until gone (max 6)
- Topical salicylic acid for 12 weeks
*not for face>refer to derm
