A Patient With Concurrent Hidradenitis Suppurativa and Porokeratosis Palmaris et Plantaris Disseminata: Case Report and Review of Autoinflammatory Keratinization Diseases

Abstract

The term autoinflammatory keratinization diseases (AIKDs) was recently proposed as a unifying concept for diseases characterized by inflammation in the epidermis and upper dermis which leads to hyperkeratosis, caused by genetic perturbations of the innate immune system. We present a case of a patient with hidradenitis suppurativa and porokeratosis, two AIKDs, followed by a review of these conditions as well as other AIKDs. This case was distinguished by hypertrophic porokeratoses involving cystic hair follicles, showing histopathologic features of both conditions within single biopsy specimens. The patient's course was additionally complicated by SCC arising within a porokeratosis. Our case demonstrates a rare overlap of two AIKDs, occurring not only within the same patient but also within the same lesions.

Keywords: autoinflammatory; case report; diseases; hidradenitis suppurativa; porokeratosis.

FIGURE 1

Clinical appearance of the patient at presentation to the dermatology clinic. (A) Verrucous, hyperkeratotic plaques with underlying interconnected sinuses involved the face and extremities, in addition to the axilla, groin, and buttocks. (B) The extremities (including palms and soles) and trunk demonstrated hyperkeratotic papules and plaques, many of which were follicular‐based.

FIGURE 2

Worsening of painful verrucous plaques on the face after 7 months of treatment with adalimumab (A) and 4 months after discontinuation of adalimumab (B).

FIGURE 3

Well‐differentiated invasive squamous cell carcinoma arising within porokeratosis. (A) Low power view (10x, H&E) demonstrates an exophytic neoplasm with a dermally infiltrating tumor composed of well‐differentiated keratinocytes. (B) High power view (40x, H&E) highlights columns of parakeratosis overlying dyskeratotic keratinocytes within the neoplasm.

FIGURE 4

Biopsy of representative lesions from the thigh (A,B) and suprapubic skin (C,D) demonstrating porokeratosis with involvement of cystic hair follicles. Low power (A, 40x, H&E) and high power (B, 100x, H&E) views demonstrating tiers of parakeratosis over dyskeratotic keratinocytes. (C) Low power (20x, H&E) view of cystic hair follicles. (D) Higher power (40x, H&E) view shows dyskeratotic keratinocytes within the follicular epithelium.

FIGURE 5

At the 16‐month follow‐up, the patient experienced an improvement in symptoms with triple therapy of infliximab, acitretin, and deucravacitinib.