Psoriasis verrucosa showing peculiar histologic features

Favorable response to apremilast in a patient with refractory psoriasis verrucosa

A 67-year-old man, who had been diagnosed with psoriasis 30 years prior, visited our hospital with a complaint of verrucous nodules in the lower legs, which had developed 15 years previously. We diagnosed him as having psoriasis verrucosa of the legs and plaque psoriasis of the torso. Because the lesions were resistant to topical glucocorticoids and vitamin D₃ , a verrucous lesion in the right leg was treated with surgical ablation, which resulted in the development of generalized pustular psoriasis. After pustular lesions were cleared by systemic glucocorticoids and methotrexate, we treated him with etretinate and cyclosporin, but the verrucous lesions accompanied by chronic bacterial infection persisted over time. One year ago, treatment with recently-approved apremilast was started. It immediately attenuated the plaques and erythropapular lesions of the trunk. Surprisingly, the verrucous nodules of both legs showed reduction in size in 2 months.

Erythrodermic verrucous psoriasis

Verrucous psoriasis is characterized clinically by symmetric hypertrophic verrucous plaques on an erythematous base and histologically by overlapping features of both verrucae and psoriasis with negative human papilloma virus (HPV) studies. A 46-year-old African-American male presented with an 8-year history of extensive malodorous, symmetric, verrucous plaques manifesting as erythroderma. Biopsies showed epidermal hyperplasia and papillomatosis, parakeratosis with neutrophils, and dilated vessels in the dermal papillae. The polymerase chain reaction of lesional skin was negative for HPV DNA, and T-cell gene rearrangement was negative. The patient was diagnosed with erythrodermic verrucous psoriasis. Verrucous psoriasis is a rare presentation of psoriasis and has only been reported as a localized variant. To the authors' knowledge, erythrodermic verrucous psoriasis has not been reported. This presentation was a diagnostic and therapeutic challenge and serves to heighten the awareness of a unique variant of psoriasis.

Verrucous Psoriasis: A Distinctive Clinicopathologic Variant of Psoriasis

Psoriasis is capable of presenting in a variety of clinical and pathologic guises including a rarely described variant variably termed hypertrophic or verrucous psoriasis. Herein, we describe the clinical and pathologic attributes of a large series of patients with this unusual variant of psoriasis and distinguish it from other entities in the differential diagnosis. The histopathologic features and clinical and demographic attributes of a series of 12 cases from 12 patients were reviewed by a single dermatopathologist (MM). The 12 patients consisted of 7 males and 5 females with an average age of 61.8 years (males 38-93 years, females 41-71 years). Eight of the patients were Caucasian, 3 Hispanic and 1 African-American. Six of the lesions were located on the knees, 4 involved the elbows, and 2 were seen on the dorsum of the hands (metacarpal-phalangeal joint). The clinical appearance of the lesions consisted of flesh-toned to white mammillated plaques (8 cases) and coalesced papules (4 cases). Each of the biopsies showed regular psoriasiform epidermal hyperplasia with acanthosis, hyperkeratosis, and either spongiform neutrophilic or Munro micro-abscesses. In addition, each showed papillomatosis with bowing of the peripheral rete ridges toward the center of the lesion (buttressing). At high power, epidermal neutrophils were seen in particular surmounting the tips of the suprapapillary plates with accompanying serum. Hypergranulosis and koilocytic change were not observed in any of the lesions. Human papilloma virus (HPV) immunostaining and periodic acid Schiff (PAS) special staining for fungi were negative. Verrucous psoriasis is a distinctive variant of psoriasis with overlapping clinical and pathologic features that might prompt consideration of verruca vulgaris. The presence of epidermal papillomatosis and epidermal buttressing seen in these lesions is reminiscent of the histologic features of verruca vulgaris. Similarly, the presence of coalesced papules might prompt clinical consideration of verruca vulgaris as well. It is likely that this under recognized clinicopathologic entity represents a patterned response of the epithelium to repeated trauma/irritation typical of the anatomic locations that were encountered in this series. Recognition of this entity should preempt confusion with verruca vulgaris or other entities capable of producing wart-like epidermal changes.

Annular verrucous psoriasis with exaggerated papillomatosis

Psoriasis is a disease of substantial clinical and microscopic diversity. We report a case of annular verrucous psoriasis associated with abnormal papillomatosis, resulting in finger-like projections. We believe that this finding may represent another odd histopathologic feature in psoriasis with verrucous and rupial clinical morphology.