Psoriasis is an immune-mediated chronic inflammatory disease characterized by well-demarcated, scaly, erythematous plaques. Those who present with the condition often have a family history, which supports recent research uncovering various genes implicated in its pathogenesis. The disease is also associated with other systemic complications, most notably cardiovascular disease.
This condition is found in a small percentage of patients with psoriasis and presentation varies from hyperkeratotic plaques to pustular lesions. The pustular form is known as palmoplantar pustulosis and is within the spectrum of palmoplantar psoriasis.
Psoriasis is typically a clinical diagnosis and its severity can be measured using the Psoriasis Area and Severity Index. If biopsy is performed, the histology demonstrates parakeratosis, orthokeratosis, loss of the stratum granulosum, and dilated vasculature with an inflammatory cell infiltrate. The keratinocytes present with abnormal differentiation and hyperplasia, and the presence of foci of neutrophils known as “Munro’s microabscesses” in the stratum corneum serve as the hallmark of histological diagnosis. However, it is important to note that appearance can vary based on the stage of the lesion and the subtype of psoriasis present.
Palmoplantar psoriasis can be especially limiting and difficult to treat because of its distribution. Topical steroids, topical vitamin D analogues, and narrow band ultraviolet light therapy can be effective for less severe cases. Methotrexate, biologic treatments, and apremilast can be used for more extensive disease.
This patient is HLA-B27 positive and has uveitis. The presence of the HLA-B27 allele has been associated with inflammatory bowel disease, uveitis, psoriatic arthritis, and reactive arthritis. It has also been reported to be associated with pustular psoriasis. She responded well to topical steroids and vitamin D analogues.
This case and photo were submitted by Mr. Shapiro at Nova Southeastern University College of Osteopathic Medicine, Davie, Fla., and Dr. Bilu Martin.
Dr. Bilu Martin is a board-certified dermatologist in private practice at Premier Dermatology, MD, in Aventura, Fla. More diagnostic cases are available at mdedge.com/dermatology. To submit a case for possible publication, send an email to firstname.lastname@example.org.
1.in “Evidence-Based Psoriasis. Updates in Clinical Dermatology.” (Cham, Switzerland: Springer International, 2018).
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