1. Take a thorough history
This is a condition where it really is important to establish the patient’s ideas, concerns and expectations. Try to elicit the aspects they find most troublesome – for example discomfort, itch, embarrassment, social effect and so on.
2. Examine the whole body
In a patient presenting with suspected psoriasis, examine the whole body in a good light. Examine the scalp because scaling is often very troublesome, and the nails because changes may cause significant distress to the patient. Ask about genital psoriasis, which can be painful and hugely embarrassing. Look for signs of Koebnerisation to help confirm the diagnosis.
3. Look for triggers
- Stress – psoriasis often presents after severe stress.
- Trauma – psoriasis can develop at the site of injury to skin (Koebner phenomenon).
- Drugs – ß-blockers, lithium and antimalarials can trigger psoriasis – patients going to a malarial area can use doxycycline for prophylaxis.
- Infection – guttate psoriasis often presents after ß-haemolytic strep sore throat.
4. Be alert to the psychological impact
Even if the condition does not look severe, it may have a severe psychological impact on the patient. Every year about 100 patients with psoriasis commit suicide and surveys have shown that its psychological effect is equivalent to ischaemic heart disease or diabetes.
5. Check CVD risk and other systemic conditions
Psoriasis is a systemic disease and is associated with an increased risk of ischaemic heart disease, hypertension, CVA, metabolic syndrome, erectile dysfunction, Crohn’s disease, coeliac disease, psoriatic arthropathy, inflammatory eye disease and depression. The inflammatory load of the disease is thought to cause vascular endothelial dysfunction. Do an annual check of blood pressure, smoking, alcohol, lipids and glucose.
6. Encourage lifestyle changes
Explain that psoriasis is caused by rapid skin growth, there is often a family history and there is no cure, but the condition can be controlled. Encourage the patient to stop smoking and reduce alcohol consumption to reduce the vascular risk associated with psoriasis. The online version of this article includes details of patient associations.
7. Consider concordance when prescribing topical treatments
When prescribing topical treatment, write instructions for the patient on where, when and how it is to be used. If the patient has very large plaques, if there are lots of small plaques or plaques are inaccessible, concordance will be poor. Use emollients first line for all types of psoriasis and advise patients to stop using soap. Take care with superpotent topical steroids – these can precipitate pustular psoriasis.
8. Refer generalised pustular psoriasis and erythroderma immediately
If you suspect generalised pustular psoriasis or erythroderma, refer as an emergency as these conditions can be life threatening.
9. Refer psoriatic arthropathy to rheumatology
If psoriatic arthropathy is present it is often best to refer to a rheumatologist or to a combined clinic, as biological therapy appears to be easier to access through rheumatology than dermatology.
10. Review the diagnosis if treatment fails
Check whether psoriasis is the correct diagnosis and then check concordance with treatment. If in doubt, refer to dermatology.
Dr Andy Jordan is a GP and hospital practitioner in dermatology in Amersham, Buckinghamshire