Dermatology+Answers+2008

=Dermatology Answers 2008=

**(1) For the following conditions describe:** **•**   **the typical types of lesions** **•**   **common locations or distribution of lesions** **•**   **whether primary or secondary** **(a) Atopic eczema in a 6 year old child** - erythema, fine scale, papules, excoriation (due to scratching), vesicles (which can burst) - extensor surfaces (e.g. wrists and limbs, flexures), face - primary and secondary (excoriation)

- lichenification (thickening) due to scratching, fibrotic nodules and post-inflammatory hyper or hypo-pigmentation due to chronic inflammation - face, neck, flexor surfaces of joints, hands - primary and secondary (lichenification)
 * (b) Chronic atopic eczema in an adult**

//caused by infections (herpes-simplex) and medications// - vesicle, target lesions (urticated papules), blistering bullae if severe - primarily on distal parts of the limbs (palms and soles), mucous membranes, but may be widespread (more likely Stevens-Johnson) - primary **(d) A chronic user of potent topical corticosteroids** - telangiectasia (capillaries on surface of the skin), corticosteroid purpura, striae (stretch marks due to collagen breaking down), pustulation, atrophy (thinning), local hypertrichosis - distributed across areas where products have been used - primary **(e) Severe acne vulgaris** - nodulo-cystic lesions (chronic), inflammatory lesions (large papules, pustules and cysts), erythema, ice-pick scars on cheeks, keloidal scars on shoulders/mid-chest, comedones (white/blackheads - high numbers on face, back, chest and shoulders - primary and secondary **(2) For the following vehicles list the main uses and adverse effects. Provide an** **example of each type.** **(a) cream (oil in water)** //vehicle best disperses in moisture (like and like)// uses: moist areas, vesicular, bullous or exudative dermatoses, face, hair bearing SEs: may be excessively drying, preservatives examples: aqueous, sorbolene, cetomacrogol, salicylic acid and coal tar cream
 * (c) Erythema multiforme**

//not good if moist, as it will not mix in with moisture// uses: dry, scaly conditions (prevents moisture loss, better penetration, stays on longer) SEs: greasy, uncomfortable, may cause maceration and secondary folliculitis (blockage), allergy if wool fat examples: paraffins, emulsifying ointment, cetomacrogol emulsifying ointment uses: oozing areas, plaques, warts, lichenified areas SEs: difficult to apply and remove, uncomfortable (remove using liquid paraffin) examples: Zinc, Lassar's, Upton's
 * (b) ointment**
 * (c) paste**

uses: moist areas (absorbs moisture and wound doesn't need to be touch - less friction) SEs: should be avoided in fungal infections if contain starch examples: talc, miconazole dusting powder
 * (d) powder**

**•** **diclofenac 50mg three times a day (commenced 10 days ago)** **•** **atorvastatin 40mg nocte** **•** **metoprolol 100mg twice daily** **•** **Augmentin Duo Forte one tablet daily (commenced 3 days ago)** **(a) Based on the clinical presentation, what are the possible options for the diagnosis of** **the rash?** - psoriasis vulgaris (most likely) - seborrheic dermatitis
 * (3) Mr DS, a 45 year old man, presents complaining of rash which has spread** **progressively over the last two weeks. On examination, the lesions are thickened** **and scaly on a red background. A silvery white shimmer is also seen. There are** **large lesions on the knees and elbows and some smaller ones on the arms and legs.** **There are also some thinner lesions along the scalp margin.** **He is currently suffering from mild bronchial pneumonia.**
 * Current medications** **:**
 * Social** **: Mr BH lives on his own having recently separated from his wife.**

- immune-mediated by a chronic T-cell dependent inflammatory process - mediated by tumour necrosis factor and other inflammatory cytokines - activated T-cells in the skin set off a chain of events leading to rapid growth of skin cells causing characteristic lesions - dermal capillaries expanded
 * (b) What is the basic underlying abnormality of this condition?**

**(c) What factors in this presentation are suggestive of the diagnosis?** //eczema - more itchy psoriasis - simply uncomfortable// - lesions are thickened and scaly on a red background - silvery white shimmer - large lesions on elbows and knees, smaller ones on arms and legs - thinner lesions along scalp margin (rules out eczema and seborrheic dermatitis)

- stress (recently separated from wife) - infection (mild bronchial pneumonia) - NSAID (diclofenac) - beta-blocker (metoprolol)
 * (d) What factors may have precipitated this skin condition in Mr DS at this time?**

- emollient: deposits an occlusive oily film that reduces transepidermal water loss - keratolytics: facilitates removal of scale, decreases hyperkeratosis (decrease cohesion of cells in stratum corneum) - tar preparations: suppresses DNA synthesis in epidermis - topical corticosteroids: exert anti-inflammatory and immunosuppressive effects (inhibit protein synthesis and mitosis in DNA - if mild) - dithranol: decreased DNA synthesis by complexing DNA (severe plaques)
 * (e) List four types of topical therapy which may be useful in Mr DS’s** **treatment plan. Briefly describe the mode of action of each.**

- retinoids (acitretin) - not if hypertriglyceraemia - PUVA (psoralen UV-A) - can try this first (not in skin cancer) - methotrexate (complete blood examination, understand dosing schedule, may help arthritis), cyclosporin (increases BP, not if concomitant infection) - etanercept, infliximab, efalizumab, adalimumab, alefacept
 * (f) If the skin condition does not respond to an appropriate trial of topical therapy, what** **oral or systemic medications might be considered.**

- topical corticosteroids as they can be used on flexures and face (mild or moderate) - other topical therapies including tars - methotrexate most of these therapies were ruled out due to some contraindication (medication or condition)
 * (g) Which would you recommend as the most appropriate to try first and why?**