January 2025 Medical Image of the Month: Psoriasis with Pulmonary Involvement
Figure 1. Axial lung-windowed CT reconstructions through the mid (A,B) and lower (C) lungs from a 58-year-old man with psoriasis presenting for evaluation of interstitial lung disease. There is peripheral and lower lung predominant reticulation, ground glass, and traction bronchiolectasis with architectural distortion and atelectasis. To view Figure 1 in a separate enlarged window click here.
Figure 2. Low-power (A) and high-power (B,C) hematoxylin & eosin-stained pathology slides from a surgical lung biopsy (left lower lobe) demonstrating scattered lymphoid aggregates with patchy granulomatous organizing pneumonia and scattered loosely formed nonnecrotizing granulomas, concern for underlying systemic connective tissue disease-related interstitial lung disease. To view Figure 2 in a separate enlarged window click here.
A 58-year-old man presented to our pulmonary service for a second opinion concerning his interstitial lung disease (ILD), which had been diagnosed as rheumatoid arthritis associated ILD. The patient had a positive rheumatoid factor (barely) at an outside institution, but no other test results or historical or physical exam findings to suggest rheumatoid arthritis. He was being treated with mycophenolate, but did not feel that he was improving. To the contrary, there had been a recent decline in his overall lung function. The only other relevant medical history is psoriasis. The patient is a lifelong nonsmoker. Resting pulse oximetry was 95% on room air with a brief desaturation to 88% during ambulation, which quickly recovered with rest. The patient’s vital signs were otherwise normal. Physical exam findings were normal aside from mild cutaneous findings of plaque psoriasis. Results from pulmonary function testing at an outside institution were available, revealing a forced vital capacity 40% of reference and DLCO 37% of reference. The overall picture was consistent with restrictive lung disease. Images from an outside CT (Figure 1) demonstrated patchy findings of ILD with peripheral and lower lobe predominant reticulation, ground glass, and architectural distortion without any significant honeycombing or air trapping. The pattern was felt to be pretty nonspecific, but most consistent with ILD in the setting of autoimmune disease, favoring an NSIP or OP pattern over UIP.
Slides from the patient’s outside surgical lung biopsy were reviewed by our pathology department, who have expertise regarding pulmonary manifestations of psoriasis (1). Pathology (Figure 2) showed randomly distributed lymphoid aggregates in association with mild patchy chronic inflammatory infiltrates and patchy areas of numerous macrophages filling airspaces. There were scattered foci of organizing pneumonia focally with nonnecrotizing granulomas. In addition, there were a few scattered very loosely formed nonnecrotizing granulomas. Rare eosinophils were also present. Rare foci of osseous metaplasia were also identified. While the findings were felt to be nonspecific, they are most concerning for an underlying systemic connective tissue disease involving the lung. The case was discussed at our multidisciplinary ILD conference and a consensus diagnosis of ILD related to psoriasis was made. There is limited data suggesting possible improvement in psoriatic ILD with psoriasis treatment using secukinumab (2). However, there are also reports of secukinumab exacerbating ILD in the setting of psoriasis (3). Given the patient’s lack of improvement on mycophenolate, a trial of secukinumab is being considered.
Interstitial pneumonia is relatively rare in the setting of psoriasis, with a series of 392 psoriasis patients demonstrating an incidence of 2% (4). In this series, the most common imaging findings were lower lung predominate ground glass and reticulation, as was seen in this case. Interestingly, one case series (5) found that a UIP pattern of fibrosis was the most common pattern of ILD on CT in patients with plaque psoriasis; however, many of these patients were smokers. Concomitant smoking seems to predispose the patient towards a UIP pattern of ILD in the setting of psoriasis. In non-smokers, NSIP and OP patterns of ILD seemed more prevalent. Although rare, ILD in psoriasis is an important possibility to consider given that some patients treated with biologic agents for their psoriasis experienced improvements in their ILD (2,4).
Clint Jokerst, MD1, Yasmeen M. Butt, MD2
Departments of 1Radiology and 2Pathology
Mayo Clinic Arizona
Phoenix, AZ USA
References
- Butt YM, Smith ML, Tazelaar HD, Roden AC, Mengoli MC, Larsen BT. Surgical Pathology of Diffuse Parenchymal Lung Disease in Patients With Psoriasis or Psoriatic Arthritis. Arch Pathol Lab Med. 2022 May 1;147(5):525-533. [CrossRef] [PubMed]
- Miyachi H, Nakamura Y, Nakamura Y, Matsue H. Improvement of the initial stage of interstitial lung disease during psoriasis treatment with secukinumab. J Dermatol. 2017 Dec;44(12):e328-e329. [CrossRef] [PubMed]
- Kajihara I, Yamada-Kanazawa S, Maeda-Otsuka S, Jinnin M, Akaike K, Ihn H. Secukinumab-induced interstitial pneumonia in a patient with psoriasis vulgaris. J Dermatol. 2017 Dec;44(12):e322-e323. [CrossRef] [PubMed]
- Kawamoto H, Hara H, Minagawa S, Numata T, Araya J, Kaneko Y, Umezawa Y, Asahina A, Nakagawa H, Kuwano K. Interstitial Pneumonia in Psoriasis. Mayo Clin Proc Innov Qual Outcomes. 2018 Sep 20;2(4):370-377. [CrossRef] [PubMed]
- Rizzetto G, Tagliati C, Fogante M, et al. CT Patterns of Interstitial Lung Disease in Patients with Plaque Psoriasis: A Retrospective Case Series Study. Medicina (Kaunas). 2023 Sep 12;59(9):1650. [CrossRef] [PubMed]