UKMLA passmed(Derm) Flashcards
Erythema Multiforme
- Hypersensitivity reaction
Features: (think red targets) - Target lesions (NB: eryThema=Target lesions): red, circles(look like target shop sign0
- Affects upper limbs more, seen on back of hands/feet before spreading to torso
Causes: virus, bacteria, idiopathic, malignancy - If have mucosal involvement= severe form: Erythema multiforme major
Erythema Nodosum
Features: Nodular lesions(that are tender and red) (think Red Nodes: name)
- Resolves within 6 weeks and lesions heal without scarring
Causes:
- Infection= TB, Strep, systemic disease (sarcoidosis), malignancy, drugs, pregnancy
Guttate Psoriasis
- Precipitated by Strep. infection 2-4 weeks before lesions appear.
- Features: tear drop pattern, is more common in children and adolescents.
- lots of small pink spots all over body
- Management: resolve spontaneously within 2-3 months, topical agents (similar to psoriasis), phototherapy
Differences to Pityriasis Rosea (PR)(similar condition):
- PR: Acute,self-limiting rash, fir tree, herald patch erythematous appearance, self-limiting and resolves after around 6 weeks, affects young adults
Acne Vulgaris*:
Types:
1. Comedones: closed top=whitehead, open top= blackheads
2. Inflammatory: Papules and Pustules
3. Excessive inflammatory: Nodules and Cyst
Classified into mild, moderate, severe: Mx=
- Mild: 12 wk of topical Adapalene+benzoyl peroxide, topical tretinoin with clindamycin, topical benzoyl peroxide+clindamycin
- Moderate: 12 wk course: add either oral lymecycline or doxycycline (NB: Tetracyclines- avoid in pregnant and breastfeeding women and in children less than 12 years of age, can use Erythromycin)
-Severe:
Severe Acne: Acne Fulminans: associated with fever; hospital admission and needs oral steroids.
Animal and Human Bites
ANIMAL: Most often dogs/cats.
- Most common organism= Pasteurella Multocida
Mx: Cleanse wound (except puncture wound)
Mx: Co-Amoxiclav (if allergic to penicillin=Doxycycline+Metronidazole)
HUMAN: Cause can be aerobic/anaerobic
- Organisms: Strep, Staph
Mx: Co-Amoxiclav (same as animal bites)
Can be a risk of viral infections (HIV, Hep C)
Bed bugs (Cimex Hemipteru):
Presents:
- Itchy skin rashes
- Bites
- Allergic symptoms (secondary to infestation of bed bugs)
-are found in mattresses of fabrics and difficult to get rid of.
Mx: Topical Hydrocortisone: Suitable to control itch, definitive mx= pest management+fumigation of the house
- Can be controlled: by hot-washing bed linen+using mattress covers
Lyme disease: (Spirochaete Borrelia Burgdorferi) and spread by ticks:
EARLY features (within 30 days):
= Bull’s eye at site of tick bite (Erythema Migrans- is indication to start abx. immediately)
- Usually painless, Systemic: headache, lethargy, fever
LATE features (after 30 days):
= Cardiovascular (heart block, peri/myocarditis)
=Neurological (facial nerve palsy, radicular pain, meningitis)
Investigations: 1st line) ELISA antibodies to Borrelia burgdorferi
Mx: Doxycycline (unless pregnant=Amoxicillin)
- if disseminated(spread out) disease= Ceftriaxone
Burns: (Mx)
- Immediate first aid: ABC (Airway, Breathing, Circulation)
- Assessing depth of burns: first, second, third degree=
1st: Superficial Epidermal: Red and painful, dry, no blisters
2nd: Superficial dermal: Pale pink, painful, blistered, slow cap refill
2nd: Deep dermal: typically white (patches of non-blanching erythema)
3rd: Full thickness (white/brown/leathery/black in colour, no blisters, no pain)
Acanthosis Nigricans:
- Symmetrical, brown velvety plaques= found on neck, axilla, groin
- Causes: T2DM, GI cancer, Obesity, Cushing’s Disease
Pathophysiology: Insulin resistance= Hyperinsulinaemia= stimulation of keratinocytes (IGFR1)
Lichen Planus: (Skin disease of unknown cause, immune-mediated)
Features:
- Itchy papular rash most common on palms, soles
- Rash: Polygonal in shape with ‘white lanes’
- Koebner phenomenon: New skin lesions appearing at site of trauma.
- Oral involvement: in around 50% of patients, nails: thinning of nail plate, longitudinal ridging
Mx: Potent topical steroids=main treatment, Benzydamine mouthwash= Oral lichen planus
Rosacea: (chronic disease of unknown cause)
Features:
- Typically affects nose, cheeks, forehead
- Flushing: is often first symptom
Telangiectasia is common
- Sunlight: may exacerbate symptoms
- Later develops into erythema+papules+pustules
- Ocular movements: Blepharitis (Swollen, itchy eyelids)
MX: sunscreen, flushing= topical Brimonidine gel, mild-moderate pustules: Topical Ivermectin=1st line
Moderae-severe: Topical ivermectin+ oral Doxycycline
Seborrhoeic Dermatitis (adults and children)
ADULTS:
- is chronic, thought to be caused by fungus= Malassezia furfur (P.ovale)
- is common
MX: 1st line treatment= Ketoconazole 2% shampoo/ shampoo with zinc
Can also use: Topical steroids= best used for short periods.
- Is hard to treat as recurrences are common.
CHILDREN:
- Common in children, affects the scalp (CRADLE CAP), nappy area, face and limb flexures.
Cradle Cap: early sign that may develop in first few weeks of life, erythematous rash+coarse yellow scales
- Mx: resolves within a few weeks, can try a topical emollient onto scalp, severe= topical imidazole cream.
Tends to resolve spontaneously by around 8 months of age.
Eczema Herpeticum
Very severe infection of skin caused by:
- Herpes Simplex Virus 1/2
- More commonly seen in children with atopic eczema= rapidly progressing painful rash
- O/e: Monomorphic punched out lesions (circular, depressed ulcerated lesions)
- Mx: Life-threatening, children should be admitted: IV Aciclovir
Eczema in children+topical steroids
Basal cell Carcinoma
