What investigations are necessary to assess for underlying conditions in patients with Raynaud's phenomenon?

To assess for underlying conditions in patients presenting with Raynaud's phenomenon, a targeted clinical and laboratory evaluation is necessary to distinguish primary from secondary causes, particularly connective tissue diseases.

Initial investigations should include:

• Detailed clinical history and examination focusing on features suggestive of secondary Raynaud's, such as digital ulcers, severe or frequent episodes, and signs of connective tissue disease ¹.
• Blood tests including antinuclear antibodies (ANA) to screen for autoimmune connective tissue diseases, rheumatoid factor, and anti-cyclic citrullinated peptide (anti-CCP) antibodies to evaluate for rheumatoid arthritis ¹,⁴.
• Additional serological tests may include extractable nuclear antigen antibodies (e.g., anti-Scl-70, anti-centromere) to identify systemic sclerosis and other specific autoimmune conditions (Devgire and Hughes, 2019).
• Inflammatory markers such as erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP) to detect systemic inflammation ¹.
• Capillaroscopy (nailfold capillaroscopy) is recommended in specialist settings to detect microvascular abnormalities characteristic of secondary Raynaud's phenomenon (Lis-Święty, 2019; Devgire and Hughes, 2019).
• In cases with digital ischemia or ulceration, vascular imaging such as Doppler ultrasound may be warranted to assess for proximal large vessel occlusive disease ¹.

Additional considerations: In children or young patients, referral to paediatric rheumatology is advised due to the higher likelihood of secondary causes and the need for specialist assessment ¹[(Rigante et al., 2017)].

Overall, the UK guidelines emphasise early identification of secondary causes through clinical assessment and serological testing, with specialist referral for further investigations and management as needed ¹. Recent literature supports these recommendations and highlights the utility of capillaroscopy and specific autoantibody panels to improve diagnostic accuracy (Lis-Święty, 2019; Devgire and Hughes, 2019).