Dermatology Flashcards
Treatment for scabies?
Crusted scabies?
- Permethrin 5% is first-line
- Malathion 0.5% is second-line
- Pruritus persists for up to 4-6 weeks post eradication
Crusted scabies is seen in patients with suppressed immunity, especially HIV. Ivermectin is the treatment of choice.
Management for chronic plaque psoriasis?
- Regular emollients may help to reduce scale loss and reduce pruritus
- First-line: a potent corticosteroid applied once daily plus vitamin D analogue applied once daily
should be applied separately, one in the morning and the other in the evening). For up to 4 weeks as initial treatment. - Second-line: if no improvement after 8 weeks then offer:
a vitamin D analogue twice daily. - Third-line: if no improvement after 8-12 weeks then offer either: A potent corticosteroid applied twice daily for up to 4 weeks, or
a coal tar preparation applied once or twice daily. - Short-acting dithranol can also be used
Examples of vitamin D analogues include calcipotriol (Dovonex), calcitriol and tacalcitol.
they work by ↓ cell division and differentiation → ↓ epidermal proliferation.
Unlike corticosteroids they may be used long-term.
Unlike coal tar and dithranol they do not smell or stain.
They should be avoided in pregnancy
Pellagra is caused by deficiency in which vitamin?
Niacin or vitamin B3.
Pellagra is a caused by nicotinic acid (niacin) deficiency. The classical features are the 3 D’s - dermatitis, diarrhoea and dementia.
Management for Flexural psoriasis?
(Face, flexural and genital psoriasis management)
- Mild or moderate potency corticosteroid applied once or twice daily for a maximum of 2 weeks
Treatment for facial hirsutism?
Topical eflornithine is the treatment of choice for facial hirsutism.
Which cancer is the most common malignancy renal transplant patients are most at risk of?
All patients who undergo renal transplantation must be commenced and remain on immunosuppression therapy for the rest of their life to prevent the risk of transplant rejection. This immunosuppression therapy results in patients having an increased risk of carcinomas as their immune system is less able to identify and destroy newly formed cancer cells or prevent infections that may cause cancer. Squamous cell carcinoma of the skin has been shown to be the most common malignancy associated with immunosuppression.
Management for actinic keratosis?
Actinic keratoses (AKs) are rough, scaly patches on the skin that are caused by excessive exposure to the sun. They can potentially develop into squamous cell carcinoma.
Fluorouracil cream: typically a 2 to 3 week course. The skin will become red and inflamed - sometimes topical hydrocortisone is given following fluorouracil to help settle the inflammation.
Which drugs can exacerbate psoriasis?
- Beta blockers
- Lithium
- Antimalarials (chloroquine and - Hydroxychloroquine)
- NSAIDs
- ACE inhibitors
- Infliximab
Common causes of acanthosis nigricans?
Describes symmetrical, brown, velvety plaques that are often found on the neck, axilla and groin.
Causes:
- Type 2 diabetes mellitus
- gastrointestinal cancer
- obesity
- PCOS
- Acromegaly
- Cushing’s disease
- Hypothyroidism
familial
- Prader-Willi syndrome
- Drugs: COCP, nicotinic acid
Treatment for acne?
- Single topical therapy (topical retinoids, benzoyl peroxide)
- Topical combination therapy (Topical antibiotic, benzoyl peroxide, topical retinoid)
- Oral antibiotics:
- Tetracyclines: lymecycline, oxytetracycline, doxycycline
- Tetracyclines should be avoided in pregnant or breastfeeding women and in children younger than 12 years of age
- Erythromycin may be used in pregnancy
- Minocycline is now considered less appropriate due to the possibility of irreversible pigmentation
- A single oral antibiotic for acne vulgaris should be used for a maximum of three months.
- A topical retinoid (if not contraindicated) or benzoyl peroxide should always be co-prescribed with oral antibiotics to reduce the risk of antibiotic resistance developing.
- Topical and oral antibiotics should not be used in combination - COCP are an alternative to oral antibiotics in women
- Oral isotretinoin: only under specialist supervision. Pregnancy is a contraindication to topical and oral retinoid treatment.
How to differentiate between bullous pemphigoid and pemphigus vulgaris?
No mucosal involvement: bullous pemphigoid
Mucosal involvement: pemphigus vulgaris
Bullous pemphigoid = Itchy tense bilsters around flexures.
Pemphigus Vulagris = Flaccid easily ruptured vesicles.
Causes of erythema nodosum?
- Inflammation of subcutaneous fat
typically causes tender, erythematous, nodular lesions
usually occurs over shins, may also occur elsewhere (e.g. forearms, thighs). - lesions heal without scarring
Causes:
Infection
- streptococci
- tuberculosis
- brucellosis
Systemic disease
- sarcoidosis
- inflammatory bowel disease
- Behcet’s
Malignancy/lymphoma
Drugs
- penicillins
- sulphonamides
- combined oral contraceptive pill
Pregnancy
What causes dermatitis herpetiformis?
Dermatitis herpetiformis - caused by IgA deposition in the dermis.
Treatment for Impetigo?
Impetigo is a superficial bacterial skin infection usually caused by either Staphylcoccus aureus or Streptococcus pyogenes.
‘Golden’, crusted skin lesions typically found around the mouth.
Limited, localised disease:
Hydrogen peroxide 1% cream for people who are not systemically unwell.
Topical antibiotic creams:
- Topical fusidic acid
- Topical mupirocin should be used if fusidic acid resistance is suspected
- MRSA is not susceptible to either fusidic acid or retapamulin. Topical mupirocin should, therefore, be used in this situation.
