Jashin J. Wu - Clinical Cases in Psoriasis

Editor

Jashin J. Wu

Clinical Cases in Psoriasis 2nd ed. 2019

To my loving wife Stephanie, who understands and allows my pursuits as an academic dermatologist.

To my son Conrad, who I hope grows to be a man of maturity, wisdom, intellect, and strength.

To my parents Shin Wu, M.D., and Jane Joaquin-Wu, M.D., who installed in me the value of hard work and perseverance, thank you for all that you have given me.

Jay

A 34-year-old male, with a history of scaly plaques since 18-years-old, presented with generalized erythema and fine scaling of his skin. He had been on adalimumab for almost a year with suboptimal results. The patient had previously failed treatment with etanercept and methotrexate 20 mg weekly used in conjunction with other biologics. Treatment with infliximab appeared to be most effective for 5 years, but lost efficacy towards the end. Phototherapy for the patient was not attempted due to scheduling issues with his work. He also endorsed hand and right knee pain in the mornings. Patient had never had a biopsy performed nor did he have any history of malignancy. He is a former smoker and drinks alcohol socially.

On physical examination, face, neck, chest, abdomen, back, arms, legs, buttocks, and groin had well-defined erythematous scaly plaques. His palms and soles were clear. The affected body surface area was 95%.

Erythrodermic psoriasis

Erythrodermic psoriasis (EP) is a rare, life-threatening variant of psoriasis characterized by widespread redness, itching, pain, and scaly skin. It is the least common subtype of psoriasis occurring in less than 3% of patients, has a variable age of onset, and appears to favor males [].

The pathogenesis of erythrodermic psoriasis is still under investigation. There is evidence, however, pointing to a prominent role of T lymphocytes interactions with macrophages, and it has been demonstrated that the ratio of Th1/Th2 response was significantly lower in EP compared to patients with psoriasis []. Patients with EP were also found to have significantly higher levels of interleukin-4 and interleukin-10 compared to both psoriasis patients and healthy controls.

It is imperative to gather a detailed history and perform a thorough exam in order diagnosis EP and initiate appropriate management. EP should be considered when a patient presents with erythema of 75% or more of body surface area involvement and skin features of psoriasis with other causes of erythroderma less likely. Patient history will usually reveal personal or family history of psoriasis, and exam may demonstrate other features consistent with psoriasis including plaques, arthralgias, and nail disease. Skin biopsy will most frequently show histological features supporting psoriasis such as hyper- and parakeratosis along with a thickened stratum spongiosum layer and reduced granular layer.