From the Guidelines
Pityriasis rubra pilaris (PRP) is a rare skin disorder that requires prompt diagnosis and treatment with azathioprine, as evidenced by limited studies suggesting its effectiveness in managing this condition. The diagnosis of PRP is primarily clinical, based on the characteristic appearance of reddish-orange patches on the skin, palmoplantar keratoderma, and follicular hyperkeratosis 1.
Key Features of Pityriasis Rubra Pilaris
- Characteristic skin lesions
- Palmoplantar keratoderma
- Follicular hyperkeratosis
- Potential for significant morbidity if left untreated or inadequately managed
Treatment Approach
Given the lack of formal studies but the presence of limited evidence supporting the use of azathioprine for PRP 1, azathioprine is recommended as a treatment option for PRP due to its potential effectiveness in managing inflammatory skin conditions. It's crucial to monitor patients for adverse events, particularly those who are heterozygous at the TPMT locus, as they may have an increased risk of nausea and other side effects, although the evidence is not conclusive 1.
Management Considerations
- Azathioprine dosing and monitoring: Should be guided by clinical response and tolerance, with careful consideration of TPMT status to minimize the risk of adverse effects.
- Supportive care: Includes keeping the skin moisturized and managing symptoms to improve quality of life.
- Regular follow-up: Essential to assess the response to treatment and adjust the management plan as necessary.
Quality of Life and Morbidity Considerations
The primary goal in managing PRP is to reduce morbidity, improve quality of life, and minimize the risk of long-term skin damage. Given the potential of azathioprine to effectively manage PRP, its use is justified despite the need for careful monitoring and consideration of potential side effects 1.
From the Research
Diagnosis of Pityriasis Rubra Pilaris
- The diagnosis of Pityriasis Rubra Pilaris (PRP) is based on both clinical and histopathological findings 2
- Clinical findings include erythema and papular eruptions, which can progress to erythroderma 2
Treatment Options for Pityriasis Rubra Pilaris
- There are numerous treatment options available, including topical and systemic agents, and physical modalities 2, 3
- Topical treatments include corticosteroids, salicylic acid, pimecrolimus, calcitriol, and calcipotriol 4, 5
- Systemic treatments include retinoids (such as isotretinoin, etretinate, and acitretin), methotrexate, cyclosporine A, and biologicals (such as infliximab, etanercept, and ustekinumab) 4, 2, 3, 5, 6
- Phototherapy, including ultraviolet B targeted phototherapy and PUVA, can also be used as a treatment option 4, 5
Recommended Treatment Regimens
- A suggested treatment regimen includes a retinoid as first-line therapy, and a combination of retinoid and methotrexate, azathioprine, or cyclosporine A as second-line therapy 2
- Biologicals can be used as third-line therapy, and can be combined with a retinoid, methotrexate, or cyclosporine A in case of treatment failure 2, 3
- Isotretinoin can be used as first-line treatment, followed by methotrexate as second-line, and biologicals as third-line treatment 3
Efficacy of Treatment Options
- Retinoids have been shown to be effective in achieving an excellent response in 42.0% of patients, with isotretinoin being the most effective (61.1%) 3
- Methotrexate has been shown to be effective in achieving an excellent response in 33.1% of patients 3
- Biologicals have been shown to be effective in achieving an excellent response in 51.0% of patients, with ustekinumab being the most effective (62.5%) 3