Differential Diagnosis

The patient presents with a complex set of symptoms, including worsening neck stiffness and pain, intermittent headaches, and right leg pain and swelling, against a background of polymyalgia rheumatica (PMR) and other comorbidities. The differential diagnoses can be categorized as follows:

• Single Most Likely Diagnosis
  • Exacerbation of Polymyalgia Rheumatica (PMR): The recent increase in prednisolone dose due to winter, a known factor that can exacerbate PMR symptoms, and the nature of the patient's complaints (worsening neck stiffness and pain, constant pain worse in the morning) are consistent with an exacerbation of PMR. The patient's history and current symptoms align closely with PMR flare-ups.
• Other Likely Diagnoses
  • Giant Cell Arteritis (GCA): Although the patient denies classic symptoms of GCA such as jaw claudication, scalp tenderness, or visual changes, the presence of worsening neck stiffness and pain, and intermittent headaches, especially in the context of PMR, warrants consideration of GCA. The absence of these classic symptoms does not rule out GCA entirely.
  • Osteoarthritis of the Neck: Given the patient's history of osteoarthritis of the neck, the worsening neck stiffness and pain could also be attributed to progression or exacerbation of this condition.
  • Deep Vein Thrombosis (DVT): The right leg pain and swelling, tenderness on deep palpation of the calf, and a possible history of unconfirmed DVT post-childbirth raise the possibility of a new DVT, especially in the context of recent decreased activity due to stress.
• Do Not Miss Diagnoses
  • Cervical Spine Fracture or Instability: Although less likely, given the absence of trauma history, the severe neck pain and restricted range of motion necessitate consideration of a cervical spine fracture or instability, which could be catastrophic if missed.
  • Malignancy: The recent onset of worsening symptoms, despite the patient being on prednisolone, could potentially indicate an underlying malignancy, which, although rare, is a critical diagnosis not to miss.
  • Infection (e.g., Osteomyelitis, Septic Arthritis): Infections in the neck or leg could present with similar symptoms and are critical to diagnose early to prevent serious complications.
• Rare Diagnoses
  • Temporal Arteritis without Classic Symptoms: Although the patient's temporal arteries are non-tender, and there are no classic symptoms of GCA, atypical presentations can occur, especially in the context of PMR.
  • Vasculitis (other forms): Other forms of vasculitis could potentially explain some of the patient's symptoms, although they are less common and would require specific diagnostic testing to confirm.
  • Neurological Conditions (e.g., Cervical Radiculopathy, Myelopathy): These conditions could explain some of the neck pain and stiffness but would typically be accompanied by neurological deficits, which are not prominently featured in the patient's presentation.