Dermatology Flashcards
What are the indications for emollients?
Dry skin, eczema, psoriasis
What are some examples of emollients?
Light creams: aqueous, dermol, cetraben, diprobase, dermol 500
Greasy preparations: hydromol, epaderm, emulsifying ointment, 50% white soft paraffin in liquid paraffin
(Dermol products also contain benzalkonium chloride and can be useful in secondary infection)
What are side effects of emollients?
These are uncommon. They include contact dermatitis and being fire hazards (emulsifying ointment and paraffin products).
What are soap substitutes used for?
Useful in dry, itchy skin conditions. Aqueous cream is satisfactory.
What are the indications for topical corticosteroids?
Inflammatory conditions such as insect bites, eczema, localised psoriasis
What is a mild topical steroid and which ones have antimicrobial properties?
Mild - hydrocortisone 1-2.5%
Anti-microbial - Canesten HC, Daktocort, Fucidin H
What is a moderate topical steroid and which one has antimicrobial properties?
Eumovate, Betnovate-RD
With antimicrobial - Trimovate
What is a potent topical steroid and which ones has antimicrobials/ salicylic acid?
Betnovate, Elocon
With antimicrobials - Betnovate-C, Fusibet
with salicylic acid - Diprosalic
What is a very potent steroid?
Dermovate
How should you tell a patient to apply their topical steroid?
No more than twice daily, once daily usually sufficient
Spread thinly
Apply about 20-30 mins after any emollient has been supplied
What are the adverse effects of steroids?
Mild and moderately potent steroids are associated with few side effects and are safe to use on children and thin skin of face and flexures.
Local SE: spread and worsening of untreated skin conditions, thinning of the skin, irreversible striae and telangeictasia, acne or worsening of acne or rosacea, hypopigmentation
What are topical calcineurin inhibitors e.g. tacrolimus used for?
Moderate to severe atopic eczema
Facial psoriasis
When would you use non-sdedating and sedating oral antihistamines?
Non-sedating: chronic urticaria e.g. fexofenadine and cetirizine
Sedating - for itching e.g. hydrozyzine, chlorphenamine, and treating underlying skin problem or systemic disease that is causing the itch
What are some examples of topical antifungals?
Imidazole antifungals e.g. clotrimazole, econazole, miconazole
Terbinafine cream - more effective but more expensive
When would you use topical antifungals?
localised infection: tinea corporis, tinea cruris, tinea manuum, tinea pedis
What instructions would you give a patient for whom you had prescribed topical antifungals?
Apply twice a day. To prevent relapse continue local antifungal for 1-2 weeks after the disappearance of all signs of infection.
When would you use systemic antifungals?
Infections of scalp (tinea capitis) or nail (tinea unguium) or if fungal infection is widespread, disseminated or intractable.
Options: terbinafine, azoles or griseofulvin.
What is pityriasis versicolor and how would you treat it?
Yeast infection
Use ketoconazole shampoo as a body wash plus topical imidazole antifungals.
If infection is widespread, treat systemically e.g. with itraconazole.
How would you treat candidiasis?
Topical imidazole antifungal e.g. clotrimazole or miconazole
How would you treat scabies?
5% permethrin cream over whole body and wash off after 8-12 hours. Repeat application after 7 days.
All members of the affected household/sexual contacts or other close contacts should be treated simultaneously, including those who are not itching.
The itch and inflammation can be treated with sedating antihistamine, emollient and topical corticosteroid.
When would you use topical vit D analogues e.g. calcipotriol?
Dovobet ointment - calcipotriol combined with betnovate. Indication: localised psoriasis.
Apply once or twice daily. Not suitable for widespread disease. Can cause local skin reactions e.g. itching, erythema, burning, parasthesia, dermatitis, but reduced if combined with a topical corticosteroid.
Avoid in disorders of calcium metabolism.
When would you use coal tar preparations?
Chronic plaque psoriasis.
What can you use to treat scaly scalps - psriasis, eczema, seb derm?
Cocois scalp ointment - coal tar solution and salicylic acid in coconut oil with applicator nozzle.
Apply to scalp once weekly and leave on overnight. Shampoo off the next morning.
What are the possible treatments for acne?
Mild - benzoyl peroxide, topical antibacterials e.g. erythromycin and clindamycin, adapalene for comedonal acne, oral antibiotics e.g. tetracycline, lymecycline, erythromycin If these fail - COCP especially Dianette Oral retinoids (only prescribed by or under the supervision of consultant dermatologist) - isotretinoin
What should you discuss with a patient before giving them isotretinoin?
Dryness of the skin and mucous membranes, nose bleeds and joint pains.
The drug is teratogenic and must not be given to women of child-bearing age unless they practice effective contraception.
Reports of depression and suicide. A causal link has not been established but discuss the possibility with the patient before initiating treatment.
Monitor liver function and blood lipids
When is methotrexate prescribed for psoriasis?
When not controlled by topical tx.
Other indications: psoriatic arthritis, RA, Crohn’s.
Prescribe with folic acid to reduce adverse effects.
What are the adverse effects of MTX?
Anorexia, nausea
Low WBC - patient should be advised to report all symptoms and signs of infection, esp sore throat
Hepatitis, liver fibrosis, rarely cirrhosis
Interstitial pulmonary fibrosis (seen in RA)
Teratogenic - men and women should avoid conception for at least 3 months after stopping
What monitoring should be done when a patient is on MTX?
FBC, U&E and LFTs before starting treatment, then repeat weekly until therapy stabilised, thereafter monthly.
When is ciclosporin used? What are potential side effects.
Severe atopic dermatitis and severe psoriasis.
SE - nephrotoxic. Long term use increases risk of skin cancer particularly in patients who have had previous phototherapy.
