Hidradenitis Suppurativa, Porokeratosis Overlap in Rare Case Study

This article was previously published by Dermatology Times^®. This version has been lightly edited.

The coexistence of hidradenitis suppurativa (HS) and porokeratosis palmaris et plantaris disseminata in a patient, both of which are now categorized under the umbrella term autoinflammatory keratinization diseases, was illustrated in a recent case study published in Journal of Cutaneous Pathology.¹

The case underscores the challenges in managing these complex, genetically influenced conditions, particularly when traditional treatments fail to provide sufficient relief.

Background and Methods

Autoinflammatory keratinization diseases was coined by Akiyama et al to describe a group of skin disorders characterized by genetic mutations that result in an innate immune system malfunction, leading to epidermal inflammation and hyperkeratosis.²

Despite the patient in this case improving, the case demonstrates the limitations of current treatment options for such complex diseases, especially when the underlying genetic causes remain unclear. | Image Credit: © Yurii Kibalnik-stock.adobe.com

Initial autoinflammatorykeratinizationdiseases included generalized pustular psoriasis and palmoplantar pustulosis. Over time, HS and porokeratosis were also recognized as part of this spectrum of diseases due to shared pathophysiology that includes inflammation within the epidermis and upper dermis.³

The patient in this case study was a 52-year-old male with a history of atopic dermatitis who presented with a 10-year history of painful nodules in the axillary and genital regions consistent with HS, alongside a 2-year history of hyperkeratotic rashes suggestive of porokeratosis palmaris et plantaris disseminata. Researchers conducted and described a detailed clinical and histopathological investigation to examine the progression and potential overlap of these conditions. Biopsies confirmed the presence of porokeratosis palmaris et plantaris disseminata, but molecular testing identified no atypical infectious causes.

Findings

Upon presentation, the patient exhibited interconnected sinus tracts with active drainage, scarring, and thick verrucous plaques across typical HS sites such as the axillae and groin, as well as nontraditional areas like the face and extremities. These plaques continued to worsen despite treatment with adalimumab, which led to the discontinuation of the drug after 7 months. A second biopsy revealed invasive squamous cell carcinoma arising within a porokeratosis lesion, which was subsequently treated with Mohs surgery.

Histopathological analysis of the patient's hyperkeratotic plaques confirmed the presence of porokeratosis palmaris et plantaris disseminata, a rare variant of porokeratosis that often involves the palms and soles. The lesions were also noted to exhibit hypertrophic porokeratosis involving cystic hair follicles, a hallmark of porokeratosis palmaris et plantaris disseminata. The treatment regimen, initially based on adalimumab, was deemed inadequate, and a more aggressive approach involving triplet therapy with infliximab, acitretin, and dapsone was initiated. Although dapsone was eventually discontinued due to anemia, the patient showed improvement with the remaining treatments.

Sixteen months after starting triplet therapy, the patient showed noticeable improvement, with reduced drainage from HS lesions and some regression of the hyperkeratotic plaques. The addition of deucravacitinib, a newer agent, further contributed to symptom management.

Conclusions

This case emphasizes the complexities in diagnosing and managing autoinflammatory keratinization diseases, particularly when 2 conditions overlap, as seen with HS and porokeratosis palmaris et plantaris disseminata. The patient's response to treatment highlights the challenges clinicians face when conventional therapies fail, necessitating a more tailored, multipronged therapeutic approach.

However, despite the patient's improvement, the case demonstrates the limitations of current treatment options for such complex diseases, especially when the underlying genetic causes remain unclear.

"To our knowledge, ours is the first reported case of squamous cell carcinoma arising in a porokeratosis in a patient with concurrent hidradenitis suppurativa," according to the case report’s authors. "More studies aimed at better understanding the disease pathogenesis and underlying genetic factors behind [autoinflammatory keratinization diseases] may help expand the treatment arsenal for refractory, challenging cases."

Furthermore, although the patient’s response to treatment was encouraging, the recurrence of porokeratosis and the development of squamous cell carcinoma in the lesion highlight the ongoing need for vigilant monitoring. As the field of autoinflammatory keratinization diseases continues to evolve, the recognition of diseases like HS and porokeratosis palmaris et plantaris disseminate within this framework may lead to new insights into their genetic underpinnings and treatment strategies.

References

1. Rogers MC, Ash M, Hernandez A, Hosler GA. A patient with concurrent hidradenitis suppurativa and porokeratosis palmaris et plantaris disseminata: case report and review of autoinflammatory keratinization diseases. J Cutan Pathol. Published online January 3, 2025. doi:10.1111/cup.14774

2. Akiyama M, Takeichi T, McGrath JA, Sugiura K. Autoinflammatory keratinization diseases. J Allergy Clin Immunol. 2017;140(6): 1545-1547. doi:10.1016/j.jaci.2017.05.019

3. Blicharz L, Czuwara J, Rudnicka L, Torrelo A. Autoinflammatory keratinization diseases-the concept, pathophysiology, and clinical implications. Clin Rev Allergy Immunol. 2023;65(3):377-402. doi:10.1007/s12016-023-08971-3