Pityriasis rubra pilaris in association with squamous cell carcinoma of the lung: A case report and literature review
Year: 2025
Type: article
Abstract: Dear Editor, Pityriasis rubra pilaris (PRP) is an uncommon dermatological condition characterized by erythematous scaly plaques and folliculocentric papules. We present a distinctive case of PRP concomitant with pulmonary squamous cell carcinoma, emphasizing the necessity of thorough evaluation and interdisciplinary management in such instances. A 74-year-old man without significant medical history presented with erythematous pruritic scaly plaques and folliculocentric papules over the head, neck, upper trunk, and extremities for 20 days [Figure 1a-d]. The eruption initially emerged on the face, scalp, and neck, extending to the upper chest and distal extremities. Palmoplantar keratosis with a waxy appearance was also observed. There was no mucosal involvement, other systemic symptoms, or family history of psoriasis.Figure 1: Clinical presentation initially (a-d), rapid progression within 10 days (e-h), partial improvement after acitretin treatment (i-l).The patient was admitted for the management of PRP. Despite a week of treatment with intravenous methylprednisolone and antihistamines, the erythematous papuloplaques coalesced to form large salmon-colored plaques with sparing islands that progressively advanced caudally [Figure 1e-h]. Systemic glucocorticoid treatment was discontinued, and oral cyclosporin was initiated owing to poor effects and recalcitrant pruritus. Skin biopsy confirmed the diagnosis of PRP, revealing spongiosis, extravasated erythrocytes in the upper dermis, and alternating orthokeratosis and parakeratosis [Supplementary Figure 1]. Subsequently, the treatment was transitioned to methotrexate (15 mg/week) and azathioprine (100 mg/day), supplemented by narrow-band ultraviolet B radiation for the entire body and acral ultraviolet B radiation.Supplementary Figure 1: Histological findings with characteristic alternating orthokeratosis and parakeratosis, H and E, ×100The patient had a 50-year history of heavy smoking. Eight months before this presentation, he experienced a chronic cough with blood-tinged sputum without significant weight loss. Imaging 6 months ago revealed increased infiltration of the right lower lung without mass formation. Klebsiella pneumoniae was isolated from bronchoalveolar lavage specimens. A decreased cough was noted after treatment with antibiotics. During this admission for PRP treatment, given his history of chronic cough and abnormal chest radiography findings, chest computed tomography (CT) was repeated. It revealed a pneumonia-like lesion within the right middle lobe of the lung and suspected metastatic lymphadenopathy in the right paratracheal region. Bronchoscopic biopsy confirmed Grade 2 squamous cell carcinoma of the lung. Brain magnetic resonance imaging was negative for metastatic involvement. Consequently, the patient was transferred to the chest ward. The primary therapeutic approach for the skin condition was adjusted to acitretin (25 mg/day), resulting in partial improvement of erythema and scaling [Figure 1i-l]. The patient was transferred to another medical center for lung cancer treatment and continued oral acitretin therapy. According to his family, his skin condition gradually improved following radiotherapy and chemotherapy with nivolumab, paclitaxel, and carboplatin. Unfortunately, the patient succumbed to pneumonia and bacteremia 3 months after beginning cancer treatment. PRP is a rare inflammatory papulosquamous disorder characterized by follicular papules on an erythematous base, coalescent orange-red plaques, and islands of sparing predominantly on the trunk and extremities, as well as waxy keratoderma localized to the palms and soles. Several hypotheses of the pathogenesis have been proposed, including the upregulation of tumor necrosis factor-alpha, abnormal vitamin A metabolism, potential infectious triggers, and genetic predispositions. Diagnosis typically relies on clinical and histopathological correlation, with histological features of alternating orthokeratosis and parakeratosis, follicular plugging, psoriasiform hyperplasia, and perifollicular shoulder parakeratosis. Treatment options for PRP encompass emollients, keratolytic agents, systemic retinoids, immunosuppressants, and biologics. However, there is no established treatment guideline for PRP, and the condition frequently proves resistant to therapy. Paraneoplastic PRP is a rare entity, with approximately 20 cases documented in the literature [Supplementary Table 1]. Reported malignancies include those of the breast, lung, kidney, liver, prostate, colon, bile duct, skin, and hematologic system.[1-8] The pathogenesis of paraneoplastic PRP remains poorly understood; the overproduction of growth factors by the underlying malignancy, immunological responses, and antigen cross-reactivity with the skin may contribute to the disease. PRP may occur before, with, or after malignancy diagnosis. Systemic therapies are generally insufficient without concurrent cancer control, and clinical outcomes often improve following malignancy treatment in these patients. Recognizing PRP as a potential paraneoplastic sign may prompt earlier malignancy detection. Therefore, age-appropriate cancer screening is recommended in patients with atypical or treatment-resistant PRP. Current evidence remains limited to small, heterogeneous case series, underscoring the need for broader data.Supplementary Table 1: Cases of pityriasis rubra pilaris associated with malignancyWe report the first case of PRP with lung squamous cell carcinoma in Taiwan, possibly the first reported Asian case. This case suggests a possible relationship between PRP and pulmonary squamous cell carcinoma. Dermatologists should maintain a high suspicion for paraneoplastic syndromes in new onset or recalcitrant PRP, as early identification and treatment of the underlying malignancy may lead to significant improvement in skin conditions. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent form. In the form, the patient has given his consent for his images and other clinical information to be reported in the journal. The patient understands that his name and initials will not be published and due efforts will be made to conceal his identity, but anonymity cannot be guaranteed. Data availability statement Data sharing is not applicable to this article as no datasets were generated or analyzed during the current study. Financial support and sponsorship Nil. Conflicts of interest Prof. Cheng-Che E. Lan, the EIC at Dermatologica Sinica, had no role in the peer review process of or decision to publish this article. The other authors declared no conflicts of interest in writing this paper.
Source: Dermatologica Sinica
Authors: Chin-Yu Lee, Hsin-Hui Hsu, Cheng-Che E. Lan, Sheng-Yiao Lin
Language: English
Subfield: Immunology
Field: Immunology and Microbiology
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $70
OpenAlex ID: W4412915556