Dermatology Answers 2007


AC is an 18 year old female presenting to the pharmacy with an intensely itchy and erythematous rash on her wrists, in the flexures and on her lower legs. There are areas of crusted, scaly and scratched skin and areas which are thickened and wrinkled looking, the condition has recently worsened. Current medications include beclomethasone, salbutamol and cetirizine.
1. What are the possible diagnoses for AC’s rash and why?
- eczema: intensely itchy, occurs with personal or family history of atopy (hayfever and asthma). Distributed on face, neck, flexor surfaces of joints and hands
- psoriasis: dry, scaling plaques with erythema - usually affects elbows and knees, scalp. trunk and lower extremities, fingernails and toenails, flexures may have thin plaques

2. List factors that may have contributed to the recent worsening of the skin condition.
If eczema, avoid offending agents such as:
- drying agents (soap, hot water, low humidity)
- wool clothing, pets
- complex topical medications, perfumed products
- stress or certain foods (if applicable)

If psoriasis, precipitating factors include:
- skin injury (mechanical, ultraviolet or chemical injury)
- emotional factors (stress)
- infections (viral, HIV, streptococcal)
- drugs (NSAIDs - indomethacin, lithium, quinine/chloroquine, quinidine, betablockers, some ACEi, systemic corticosteroids - withdrawal)

3. List important points to consider in the diagnosis of skin conditions.
large number of conditions often with similar appearance
physical examination
- conduct in good light
- palpation (to detect tenderness, thickened, hardened or soft lesions)
- morphology of lesions (type, colour, size)
- distribution and arrangement of lesions
- all skin should be examined (mouth, nails, hair, genital areas and eyes)

history
- chronology (date of onset, duration, previous episodes)
- evolution of lesion (first location and appearance)
- medications (topical and systemic therapies)
- recent and past illness (infections, diabetes, atopy, skin conditions)
- other (occupation, environmental conditions, travel, family history, psychological factors)

Mr WR, a 51 year old man, lives on his own and has a long history of excessive alcohol consumption. He presented to his doctor some months ago with an exacerbation of his chronic plaque psoriasis. He was treated with dithranol for initial therapy of scalp and body plaques. There is no other medical history of interest. As the topical therapy alone has not been successful, his doctor is now considering oral therapy.
His other medications are:
- Piroxicam 20mg mane
- Atorvastatin 80mg mane

4. Which oral medications are available for this indication?
non-oral
- 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)
- PUVA (psoralen UV-A) - can try this first (not in skin cancer)

oral
- retinoids (acitretin) - not if hypertriglyceraemia
- methotrexate (complete blood examination, understand dosing schedule, may help arthritis), cyclosporin (increases BP, not if concomitant infection)
- etanercept, infliximab, efalizumab, adalimumab, alefacept

5. Which would you recommend as the first choice and why?
Cyclosporin would be the first choice
not indicated:
retinoids - is on atorvastatin (hypertriglyceraemia)
methotrexate - liver damage (excessive alcohol consumption)
antibody/biological agents - last line

6. With regard to eczema and contact dermatitis, which of the following is correct?
a) Atopic eczema commonly presents in young children and is often accompanied by overgrowth of yeast
b) Moderate strength topical corticosteroids are the mainstay of treatment for atopic eczema and may be
a
pplied liberally to all areas of the face and body
c) Atopic eczema is a chronic, relapsing skin condition often occurring in individuals with a personal or family history of atopy
d) Avoiding agents which may dry or heat the skin such as soaps, hot water and wool clothing is an important counselling point for patients with contact dermatitis

a) Atopic eczema affects 5-15% of school children, 2-10% of adults. It is non-specific inflammatory response of the skin to endogenous (individual susceptibility) and exogenous factors - it is not a fungal infection. Secondary infection is common (especially in children due to scratching), usually bacterial (S. aureus, indicated by honey-coloured crusts, extensive weeping and folliculitis) or viral (herpes simplex where grouped or punched out erosions are present).
b) Hydration and topical corticosteroids are common forms of treatment for atopic eczema, with topical corticosteroids being the mainstay treatment. Moderate strength preparation for body (betamethasone valerate 0.02% cream) 2 hours under occlusion/wet packs for 1-2 days. Use a mild corticosteroid for the face (hydrocortisone 1% or alclometasone 0.05%). Lotion for the scalp.
c) Atopic eczema is a chronic, relapsing, pruritic form usually occuring with personal or family history of atopy (hayfever or asthma)
d) If eczema, avoid offending agents such as:
- drying agents (soap, hot water, low humidity)
- wool clothing, pets
- complex topical medications, perfumed products
- stress or certain foods (if applicable)

Therefore, c) and d) are correct

7. With regard to topical pharmaceutical preparations, which of the following is correct?
a) Emollient creams are very effective in the management of dry skin conditions and should be applied sparingly
b) Ointments are very effective in the management of dry skin conditions and increase hydration by emollient and occlusive actions
c) A paste formulation is often useful for ‘oozing’ skin conditions, particularly for lesions in the scalp
d) Lotions and creams are cosmetically acceptable and, as they contain no preservatives or stabilizers, do not cause sensitization

a) Creams are used in conditions with moist areas, vesicular, bullous or exudative dermatoses, face or hair bearing. Emollient creams can be used to help hydrate the skin, but there is no reason to apply them sparingly (as done with topical corticosteroids).
b) Ointments are used in dry, scaly conditions as they have an emollient, protective and occlusive effect.
c) Pastes are used for oozing areas, plaques, warts, lichenified areas. Lesions in the scalp treatment may be better suited to creams, lotions and gels as they are easy to apply to hair bearing areas - pastes are difficult to apply and remove.
d) Creams are cosmetically acceptable, but lotions are not as they may cake on the skin (calamine lotion). Creams contain preservatives, but both lotions and creams can cause sensitisation.

Therefore, b) is correct