Pre-Treatment Workup for Severe Psoriasis

General Pre-Treatment Assessment

A comprehensive laboratory and clinical assessment must be performed before initiating systemic therapy for severe psoriasis in a healthy patient, based on the specific treatment being considered, as recommended by the British Medical Journal 1, 2
Complete history and physical examination, with special attention to skin lesions not typical for psoriasis, which should be biopsied before starting treatment, is necessary 1, 3
Assessment of disease severity using objective measures, such as body surface area and PASI, and subjective impact, such as DLQI, is essential 2

For PUVA therapy, liver function tests, eye examination to rule out cataracts, assessment for history of skin cancer or previous UV/radiation therapy, and minimum phototoxic dose determination are required 1, 3
For Methotrexate therapy, full blood count, liver function tests, serum creatinine measurement, liver biopsy consideration before starting therapy, eye examination for cataracts, assessment of pregnancy status/contraception needs, and screening for drug interactions are necessary 3, 4, 5, 6
For Etretinate/Retinoids therapy, full blood count, serum lipids, liver function tests, and pregnancy test and contraception counseling are essential 3, 5

All systemic agents are absolutely contraindicated in pregnancy, and strict contraception counseling is essential, as stated by the British Medical Journal 1
Avoid combination of systemic agents due to additive toxicity unless absolutely necessary, as recommended by the British Medical Journal and Praxis Medical Insights 1, 7
Systemic corticosteroids should generally be avoided as they can precipitate erythrodermic psoriasis, generalized pustular psoriasis, or unstable psoriasis upon discontinuation, according to Praxis Medical Insights 7
Patients should be informed about potential drug interactions specific to their treatment, as advised by the British Medical Journal 4

For methotrexate therapy, weekly monitoring of full blood count, liver function tests, and serum creatinine initially, then every 1-2 months if stable, is recommended by the British Medical Journal 8