Psoriasis Treatment through Chemotherapy: Procedure, Safety Aspects, and Additional Information
Moderate-to-severe psoriasis can be challenging to manage, but various treatment options are available, including traditional systemic drugs, biologics, and phototherapy. This article will focus on methotrexate (MTX) and photochemotherapy (PUVA), two common treatments for psoriasis.
Methotrexate (MTX)
Methotrexate (MTX) is an established systemic treatment for arthropathic psoriasis and is also effective in moderate and severe psoriasis vulgaris, including pustular forms. MTX works by inhibiting neutrophil leukocytes, which are involved in psoriatic inflammation.
Before starting treatment with MTX, a test dose (2.5 mg orally or intramuscularly) is administered to check for hematological hypersensitivity. Regular blood monitoring (every 14 days) and liver ultrasound every six months are necessary to detect toxicity.
Side effects of MTX include acute toxicity, liver damage, leukopenia, gastrointestinal side effects, and skin reactions. Acute toxicity is rare but more common in the elderly or those with impaired renal function. Liver damage affects about 33% of patients, with 10% developing liver fibrosis and 5% liver cirrhosis over long-term use. Leukopenia requires immediate discontinuation and treatment with folinic acid. Gastrointestinal side effects can be mitigated by administering MTX intradermally if they occur.
Photochemotherapy (PUVA)
Photochemotherapy (PUVA) is a treatment that combines a psoralen drug with UVA exposure. PUVA is an effective option for plaque psoriasis but less so for more severe or erythrodermic types.
For erythrodermic psoriasis, PUVA may require longer treatment duration and higher doses, with a significant dropout rate (~29%) and potential severe complications like cardiovascular events and disease flares. PUVA's efficacy is primarily shown in plaque psoriasis; other forms may worsen after treatment.
Newer protocols such as combining phototherapy with topical corticosteroids before treatment ("cool-down period") can improve outcomes and reduce inflammation.
Additional Context
Biologics like risankizumab (an IL-23 inhibitor) are increasingly used for moderate-to-severe psoriasis, especially when traditional therapies fail, offering significant skin clearance and quality of life improvement over 12 months. Treatment guidelines recommend biologics after failure of at least one systemic therapy.
In summary, MTX remains a first-line systemic therapy for moderate-to-severe psoriasis with a well-characterized safety profile requiring close monitoring for hematologic and hepatic side effects. PUVA photochemotherapy is effective mostly for plaque psoriasis but less suitable for erythrodermic or certain severe variants due to side effect risks and less favorable outcomes. Biologics are becoming preferred for sustained control after traditional treatments.
Both PUVA and Narrowband ultraviolet B (NB-UVB) are effective therapies in psoriasis, but NB-UVB is generally preferred due to its lower risk of side effects. People undergoing PUVA should avoid using a sunbed, going out into the sun without appropriate sunscreen and clothing, and exposing their skin to the sun on the day of treatment.
After PUVA treatment, the skin may appear slightly flushed or darker, and other side effects may include dark spots, mild burning or stinging, itching, blisters, or a burn. PUVA treatment consists of an initial clearing phase and a maintenance phase, with two to three sessions per week during the initial phase and a minimum of 48 hours between each session.
- Seekers of treatments for moderate-to-severe psoriasis, including pustular forms, may find methotrexate (MTX) an effective systemic option, as it inhibits neutrophil leukocytes involved in psoriatic inflammation.
- Methotrexate (MTX) requires careful monitoring due to potential side effects like liver damage, leukopenia, gastrointestinal issues, and skin reactions.
- Photochemotherapy (PUVA), a combination of a psoralen drug and UVA exposure, is effective for plaque psoriasis, but may not work as well for more severe types or erythrodermic psoriasis, due to potential side effects and less favorable outcomes.
- Treatment guidelines for psoriasis recommend biologics after failure of at least one systemic therapy, like MTX, due to their significant skin clearance and quality of life improvements over 12 months.
- Alternatively, treatment seekers might consider other medical-conditions-related health-and-wellness approaches, such as therapies-and-treatments like Narrowband ultraviolet B (NB-UVB), which has a lower risk of side effects compared to PUVA.
- For successful PUVA treatment, it's essential to avoid sun exposure before and after sessions, and follow a maintenance phase with two to three sessions per week during the initial treatment phase and a minimum of 48 hours between each session.
