Key practice points:
- Finding a treatment that works for patients may require trial and error
- First-line topical medicines include emollients, potent or very potent topical corticosteroids, topical calcipotriol,
or a combination of these medicines
- Keratolytics such as topical salicylic acid or products containing coal tar may reduce scaling and be beneficial
for patients who have responded poorly to other topical medicines
The appropriate treatment for patients with chronic plaque psoriasis will depend on the location and characteristics
of the plaques, as well as the patient’s response and tolerance, so can require trial and error. Patient preference
is an important factor to consider when selecting topical medicines as treatments that are used regularly are more
likely to be successful.
Emollients are recommended as the basis of treatment
for all patients with psoriasis (Table 1). There is little evidence, however, to guide the choice
of emollient or optimal frequency of application.1, 2 In practice, patients can be prescribed the product
they prefer. Prescribing an emollient dispensed in a pump bottle may reduce the risk of bacterial contamination of
the emollient.
Potent topical corticosteroids, topical calcipotriol or both
medicines in combination significantly improve the symptoms of patients with chronic plaque psoriasis.
A recommended order for trialling these medicines is shown in Figure 1.
Selecting an appropriate topical formulation
Emollients, topical corticosteroids, topical calcipotriol and the combination of topical corticosteroid + calcipotriol
are available in a variety of formulations.* Creams, gels and lotions are useful for spreading over larger plaques.2 Scalp
preparations are typically liquid solutions to enable the product to spread between hair follicles. Ointments are
generally more effective for patients with trunk or limb psoriasis and thick scale, however, patients may find them
less cosmetically appealing on exposed skin and less convenient as they may stick to clothing on covered skin. Patients
may prefer applying an ointment overnight rather than during the day.3
* N.B. Topical calcipotriol is currently subsidised as a scalp solution, cream and ointment; from
1 April, 2017 the scalp solution and cream formulations will be delisted due to discontinuation of supply.
Table 1. Fully subsidised emollients.4
| |
Products
(Ingredients) |
|
Subsidised product sizes |
Subsidised brands |
| Creams |
Aqueous cream BP (SLS free) |
|
500 g jar |
AFT |
Sorbolene with glycerine
(Cetomacrogol aqueous cream + glycerol) |
|
500 g pump bottle |
Pharmacy Health |
| |
1 kg pump bottle |
Pharmacy Health |
Non-ionic cream
(Cetomacrogol wax-emulsifying + paraffin liquid + paraffin soft white + water
purified)* |
|
500 g jar |
HealthE |
Fatty emulsion
(Cetostearyl alcohol + paraffin liquid + paraffin soft white)* |
|
500 g jar |
O/W Fatty Emulsion |
| Urea cream |
|
100 g tube |
HealthE |
| Ointments† |
Emulsifying ointment
(Paraffin liquid + paraffin soft white + wax-emulsifying)* |
|
500 g jar |
AFT |
Fully subsidised
* Paraffin-based emollients may be a fire hazard, especially when used in large quantities. See NZF
for further information: www.nzf.org.nz/nzf_6237
† Paraffin soft white is currently only subsidised when used in combination with a dermatological
galenical or as a diluent for a proprietary topical corticosteroid
Scalp, trunk or limbs
|
1st or 2nd line*
|
3rd line
|
Potent topical corticosteroid
Once daily
For up to 8 weeks § †
OR
Combined topical corticosteroid + calcipotriol †
Once daily
For up to 4 weeks
|
Topical calcipotriol alone
Once or twice daily
Additional option for scalp psoriasis:
Use coal tar, sulfur and salicylic acid in coconut oil. e.g.
Coco-Scalp, applied to scaly plaques for one hour longer prior to shampooing hair
|
Face, flexures
or genitals
|
1st line
|
2nd line
|
Mild or moderate potency topical corticosteroid
Once or twice daily
For up to 2 weeks
|
Topical pimecrolimus
(unapproved indication, unsubsidised)
Twice daily
For up to 4 weeks
|
* Both treatment options have similar efficacy and rates of adverse events; either can be trialled
depending on patient preference. If symptoms are ongoing the alternative 1st or 2nd line treatment option can
be trialled, and topical calcipotriol alone used as a 3rd line option
§ Mild to moderate potency topical corticosteroids may be effective for thinner, less scaly plaques.
Consider prescribing 2–5% topical salicylic acid or an alternative keratolytic for very scaly plaques if the improvement
has not been sufficient after four weeks; see: “Topical products to remove scale may improve
the effectiveness of topical corticosteroids”
† A four week interval is recommended between treatment courses of potent or very potent topical
corticosteroids
Figure 1. Suggested prescribing order for topical medicines for the treatment of mild chronic
plaque psoriasis.2, 4, 5
Topical corticosteroids alone can be used as a first-line treatment for chronic plaque psoriasis affecting any part
of the body (Figure 1). A range of topical corticosteroids are available partly or fully subsidised
in New Zealand (Table 2).
Safe prescribing of topical corticosteroids: maximising benefit and minimising risk
Topical corticosteroids should be used intermittently, with short courses of two to eight weeks, depending on location
of use and potency (Figure 1). Prolonged use of potent to very potent topical corticosteroids is
associated with an increased risk of skin atrophy, striae and adrenal suppression.1, 2 In addition, ongoing
use of topical corticosteroids can paradoxically result in poor control of psoriasis.2 Applying topical corticosteroids
to widespread areas, e.g. 10% or more of the body, is not recommended due to the increased potential for systemic absorption;
patients with psoriasis this widespread should be referred to a dermatologist as treatment with oral medicines is likely
to be necessary.*
The use of emollients, bath oils and products containing salicylic acid may improve the response to topical corticosteroids
(see below).2
Topical corticosteroids combined with antibacterial and antifungal medicines should not be routinely used as they
provide no additional benefit for the majority of patients with psoriasis.
* The area covered by the patient’s palm with outstretched fingers (a “handprint”) is approximately
equal to 1% of their body surface area.8
Combination topical corticosteroid + calcipotriol is also an appropriate first-line treatment
Calcipotriol is a topical vitamin D analogue indicated for the treatment of psoriasis. Combination treatment with
both topical corticosteroids and topical calcipotriol is an appropriate first-line option for patients with psoriasis
on the scalp, trunk or limbs (Figure 1).2 Combination treatment can be prescribed either
as a pre-mixed formulation containing betamethasone dipropionate, available as a gel or ointment (Table
2), or topical calcipotriol (available fully subsidised as an ointment**) and a topical corticosteroid can be prescribed
separately for concurrent use; there is not clear evidence whether the pre-mixed combination formulation or use of each
product separately gives better results.6
The combination product requires one application per day as opposed to two applications when these medicines are prescribed
separately. However, prescribing separately enables a different potency of topical corticosteroid to be selected if
required, e.g. if a potent topical corticosteroid is stepped down to a mild or moderate potency topical corticosteroid
as plaques improve.
The use of calcipotriol is associated with local adverse effects (see below), however, combining treatment with a
topical corticosteroid results in less adverse effects than the use of calcipotriol alone.5
** N.B. Calcipotriol scalp solution and cream are also currently subsidised but will be discontinued
after 1 April, 2017
Calcipotriol alone is effective but associated with high rates of local adverse effects
Calcipotriol alone can be considered as a treatment for psoriasis on the scalp, trunk or limbs, applied once or twice
daily to affected areas (Figure 1).4 However, local adverse effects such as burning,
pruritus, peeling, dryness or erythema may be experienced by up to 35% of patients using calcipotriol.3 These
typically reduce with ongoing use so patients can be encouraged to persist with treatment if tolerable. Use on the face
is not recommended, and calcipotriol is more likely to irritate the flexures and groin than topical corticosteroids.11,
12 Patients should wash their hands after applying calcipotriol to prevent inadvertent application to other areas,
such as the face.
Systemic effects from vitamin D analogues, such as hypercalcaemia and altered parathyroid hormone levels, are rare
unless patients have renal disease or impaired calcium metabolism, or are applying more than 100 g per week, i.e. one
tube of calcipotriol ointment or approximately three tubes of calcipotriol + betamethasone dipropionate gel or ointment
per week.3, 4 There are no studies on the safety of calcipotriol during pregnancy, however, expert opinion
is that use on localised areas during pregnancy or breastfeeding is unlikely to result in harm from systemic absorption.12–14
Emollients containing urea or salicylic acid may reduce the effectiveness of topical calcipotriol and should be applied
at different times.9 If patients are undergoing phototherapy, calcipotriol should be applied after treatment
sessions as phototherapy inactivates calcipotriol.10
For patients with thick scale, the use of a keratolytic, such as topical salicylic acid or urea, a coal tar preparation
(Table 3), or oils such as olive oil or coconut oil, may soften plaques prior to application of
topical corticosteroids.1, 2 Coco-Scalp ointment (containing coal tar) and topical salicylic acid or urea
can be prescribed fully subsidised (see: “Prescribing topical salicylic acid”).
Coal tar products left on the skin may cause staining of clothes or skin.5 Patients may find coal tar products
used during bathing, such as bath oils or shampoos, more convenient.
Table 3. Coal tar products for patients with psoriasis. All products shown are available over-the-counter.
|
Subsidy |
Proportions of coal tar and other ingredients |
Product sizes |
| Coco-Scalp ointment * |
|
Coal tar 12% + salicylic acid 2% + sulphur 4% |
40 g |
| EgoPsoryl TA gel** |
|
Coal tar solution + sulfur-precipitated + phenol |
30, 75 g |
| Scytera foam |
|
2% coal tar |
12, 100 g |
| Polytar bath oil |
|
Tar 7.5% + cade oil 7.5% + coal tar 2.5% + arachis oil extract of coal tar 7.5% |
350 mL |
| Ionil-T shampoo |
|
Coal tar 4.25% + salicylic acid 2% |
200 mL |
| Neutrogena T/Gel shampoo |
|
Coal tar 0.5% |
200 mL |
| Polytar plus shampoo |
|
Coal tar 4% |
150 mL |
| Sebitar shampoo |
|
Coal tar solution 1% + tar 1% + salicylic acid 2% |
15, 250, 500 mL |
Fully subsidised Unsubsidised
* Coco-Scalp can be left on the scalp for an hour or longer, e.g. overnight, and then washed off4
** Use with caution on face and flexures. Do not use under occlusion.
Prescribing topical salicylic acid
Subsidised topical salicylic acid may be prepared in the pharmacy, with prescribers specifying the concentration
(recommended at 2–5%) and base. Salicylic acid is also present in coal tar combination products (Table
3) and in many unsubsidised over-the-counter skincare products.
Subsidised topical salicylic acid can be prescribed in two ways:
- Added to a proprietary topical corticosteroid formulation* (Table 2).
- Added to an emollient, e.g. salicylic acid powder 5% in white soft paraffin, 100 g; patients can apply this preparation to soften plaques before applying
a topical corticosteroid.2 There is no evidence regarding how long the interval should be between applications.
* If salicylic acid is added to a diluted corticosteroid, the prescription must be endorsed by a dermatologist for subsidy
Topical salicylic acid should:
- Not be prescribed to:15
- Women who are pregnant, due to the potential for systemic absorption
- Be used with caution in:
- Patients using topical calcipotriol: salicylic acid may reduce the effectiveness of topical calcipotriol and
these medicines should be applied at different times of the day.4, 9
- Children aged under five years: topical salicylic acid use is recommended only in small patches and in concentrations
of 0.5% or less.16
- Patients with widespread psoriasis or significant hepatic or renal impairment: the potential for toxicity, i.e.
salicylism, is increased.3, 4
Patients should be aware that a sudden onset of symptoms such as difficulty breathing, swelling in the face or feeling
faint may indicate acute hypersensitivity, although this is uncommon.17
For further information on prescribing topical products prepared in the pharmacy, see “Section C: Extemporaneously
compounded products and galenicals”, in the Pharmaceutical Schedule:
https://pharmac.govt.nz/Schedule
