Two cases of pressure ulcers related to acute calcium pyrophosphate crystal arthritis: A new concept of “disease‐specific unexpected external forces”

Abstract

Sudden‐onset immobilisation generates unexpected external forces over bony prominences and is a potential cause of pressure ulcers. Here, we report two cases of deep pressure ulcers in patients with acute monoarthritis as a result of calcium pyrophosphate (CPP) crystal deposition (pseudogout). The patients were women in their 80 who could perform activities of daily living by themselves. They developed pressure ulcers while living in their own home. Because acute CPP crystal arthritis is known to develop in relatively healthy elderly patients, patients and caregivers do not expect sudden‐onset immobilisation. In addition, larger joints are preferentially involved in acute CPP crystal arthritis, leading to the inability of patients to change positions themselves. Therefore, acute CPP crystal arthritis should be recognised as a potential causal disease for pressure ulcers. This case report further highlights a new concept of “disease‐specific unexpected external force”, which is beneficial for the prevention of pressure ulcers.

1. INTRODUCTION

Based on the definition of pressure ulcer/injury, which includes damage to the skin and underlying tissues over a bony prominence because of pressure, identification of the causal force is important for the prevention of pressure ulcers. However, it is often difficult to identify the risk factors for pressure ulcers, which increases the probability of pressure ulcer development.1 Because a pressure ulcer often develops in elderly patients, determination of the characteristics of the underlying condition may be required to identify the causal forces. Sudden‐onset immobilisation generates unexpected external forces over bony prominences and is a potential cause of pressure ulcers. However, the relationship between underlying diseases and pressure ulcer development has not been studied. Here, we report two cases of deep pressure ulcer in patients with acute monoarthritis because of calcium pyrophosphate (CPP) crystal deposition (pseudogout). Written informed consent was obtained from the two patients, and confidentiality was preserved in this report.

2. CASE REPORTS

2.1. Case 1

The patient was an 82‐year‐old woman with Alzheimer disease. She lived alone and was able to perform daily activities by herself. Then, she suddenly developed pain and swelling on her right knee. She was immobilised because of the pain for a couple of days at her home. She visited the orthopaedic department in the hospital and was diagnosed with acute CPP crystal arthritis (pseudogout) by the orthopaedist based on her radiography findings and clinical symptoms. A non‐steroidal anti‐inflammatory drug (NSAID) was prescribed, and her symptoms were alleviated. However, a deep pressure ulcer was found over her sacrum (Figure 1A). She was referred to our hospital for the treatment of pressure ulcers. At the first visit to our hospital, she was able to change her positions. Her sacral pressure ulcer was successfully treated with appropriate topical therapies (Figure 1B). As far as we know, there was no recurrence of her pressure ulcer.

Figure 1.

Pressure ulcers possibly induced by acute calcium pyrophosphate crystal arthritis. A‐B, Patient 1. A, Sacral pressure ulcer with undermining formation. B, Healed pressure ulcer after appropriate treatment and care. C‐F, Patient 2. Deep pressure ulcers over the sacrum (C), left great trochanter (D), and right heel (E). Healed sacral pressure ulcer (F)

2.2. Case 2

The patient was an 89‐year‐old woman with an unremarkable past medical history. She lived alone and was able perform activities of daily living, including walking. Thirty‐two days before her first visit, she suddenly suffered arthralgia at her hip joint. She was diagnosed with acute CPP crystal arthritis at an orthopaedic clinic and took an NSAID for the pain. According to the investigation, she slept on the tatami at her home for a while. Then, she moved to a nursing home. However, deep and large pressure ulcers were found over her sacrum (Figure 1C), left great trochanter (Figure 1D), and right heel (Figure 1E). She was referred to our hospital for the treatment of pressure ulcers. Her sacral pressure ulcer, as well as other ulcers, was treated with a combination of surgical debridement and appropriate topical therapies (Figure 1F). As far as we know, no recurrence of her pressure ulcers was reported for more than 1 year.

3. DISCUSSION

Acute CPP crystal arthritis (pseudogout) is a commonly occurring disease in the elderly2 and is a different entity from other types of arthritis such as rheumatoid arthritis and gout. Relatively larger joints, such as the knee, hip, and shoulder, are usually affected. Therefore, elderly individuals who develop acute CPP crystal arthritis could experience immobilisation within a short period of time because of pain in larger joints. Thus, CPP crystal arthritis can be a causative disease for pressure ulcers.

Another factor for the development of pressure ulcers because of acute CPP crystal arthritis is the sudden onset of the disease. Because of its sudden onset, patients and their caregivers do not expect subsequent immobilisation. Thus, support surfaces for preventive care were not provided at the onset of pressure ulcers in our two cases. Furthermore, acute CPP crystal arthritis is usually treatable by conventional medical therapy such as NSAIDs in an outpatient clinic. Therefore, immediate hospitalisation is not necessary in most cases, indicating that standard preventive care in a hospital is not always provided for patients.3

Based on the definition of pressure ulcers, identification of the external force is critical for its prevention. For bedridden patients, adequate pressure redistribution by support surface and changing position is considered standard care. However, in a patient with adequate activities of daily living (ADL), it is technically difficult to provide these measures for the prevention of pressure ulcers. Because drug‐induced pressure ulcers are caused by sudden akinesia by drug administration,4 unexpected immobilisation is a potential cause of pressure ulcer development. Similarly, Parkinson disease, which is characterised by variable mobility, can cause sudden immobilisation, leading to consequent unexpected external force.5 Indeed, the relationship between Parkinson disease and the development of pressure ulcer was reported.6, 7 However, those age‐specific causes may have been overlooked in geriatric medicine.

In conclusion, consideration of causative factors is important for the prevention of pressure ulcers in elderly individuals. These case reports highlight the importance of comprehensive care based on the disease‐specific unexpected external force, which is defined as “a force induced by substantial characters of underlying disease.” Knowledge of the common diseases in elderly individuals is required for appropriately managing pressure ulcers.

Mizokami F, Takahashi Y, Isogai Z. Two cases of pressure ulcers related to acute calcium pyrophosphate crystal arthritis: A new concept of “disease‐specific unexpected external forces”. Int Wound J. 2019;16:556–558. 10.1111/iwj.13009