What is the role of nail fold capillaroscopy (nail fold capilloroscope) in diagnosing systemic diseases like scleroderma?

Nailfold Capillaroscopy in Systemic Disease Diagnosis

Nailfold capillaroscopy is essential for distinguishing primary from secondary Raynaud phenomenon and is strongly recommended for all patients presenting with Raynaud phenomenon, as it can detect the characteristic "scleroderma pattern" that indicates underlying systemic sclerosis or other scleroderma spectrum disorders. 1, 2

Primary Diagnostic Role in Scleroderma Spectrum Disorders

Key Diagnostic Features

Nailfold capillaroscopy identifies specific microvascular abnormalities that differentiate systemic diseases from benign conditions:

• Giant capillaries are chronologically the first relevant finding for scleroderma spectrum disorders (systemic sclerosis, dermatomyositis, undifferentiated and mixed connective tissue disease) 3
• The "scleroderma pattern" includes four major pathologic findings: giant capillaries, microhemorrhages, capillary loss (avascularity), and neoangiogenesis (ramified/bushy capillaries) 3, 4
• Normal pattern shows homogeneous, parallel arrangement of capillaries in hairpin or non-specific tortuous shapes, which characterizes primary Raynaud phenomenon 3, 5

Three Evolutive Stages in Systemic Sclerosis

The technique identifies disease progression through distinct patterns 3, 4:

• Early pattern: Predominantly giant capillaries with few microhemorrhages, minimal capillary loss
• Active pattern: Frequent giant capillaries, microhemorrhages, moderate capillary loss, some neoangiogenesis
• Late pattern: Severe capillary loss with extensive avascular areas, prominent neoangiogenesis, few or absent giant capillaries

Clinical Applications Beyond Diagnosis

Screening and Monitoring in Systemic Sclerosis

All patients with systemic sclerosis should undergo nailfold capillaroscopy as part of routine assessment, as it is included in the 2013 EULAR/ACR classification criteria for systemic sclerosis. 1, 4

• Capillaroscopy should be performed using a cutaneous assessment tool at diagnosis and follow-up 1
• Capillary density is a sensitive measure of both skin and muscle disease activity 1
• Persistent capillary abnormalities are associated with longer time to remission 1
• Capillary loss has emerging predictive value for new organ involvement and disease progression, particularly for digital ulcers and pulmonary arterial hypertension 2, 6

Juvenile Dermatomyositis

Nailfold capillaroscopy plays a specialized role in pediatric inflammatory myopathies:

• Particularly useful in predicting severity of disease and monitoring clinical course in juvenile dermatomyositis 1
• Included in proposed diagnostic criteria alongside MRI, ultrasonography, and other features 1
• Should be performed with magnification using an otoscope, ophthalmoscope, dermatoscope, or formal capillaroscopy 1

Practical Implementation

When to Perform Capillaroscopy

Mandatory indications 3, 2, 5:

• All patients presenting with Raynaud phenomenon to distinguish primary from secondary causes
• Suspected systemic sclerosis or scleroderma spectrum disorders
• Patients with puffy fingers, specific SSc-associated antibodies, or other features suggesting prescleroderma 1
• Follow-up monitoring in established systemic sclerosis to assess disease progression

Technical Approach

The examination can be performed using various magnification tools 1:

• Simple clinic-based assessment: otoscope, ophthalmoscope, or dermatoscope
• Formal videocapillaroscopy for computer storage and longitudinal comparison
• Focus on nailfold of fingers (typically 2nd through 5th digits)

Limitations and Emerging Applications

Current Constraints

• In connective tissue diseases other than scleroderma spectrum disorders (systemic lupus erythematosus, psoriatic arthritis, antiphospholipid syndrome), attempts to define specific capillaroscopic characteristics have failed 3
• The general opinion about association with specific clinical manifestations in systemic sclerosis is not uniform, as microvascular changes are almost universal in scleroderma 4

Prognostic Value

The speed of progression of microvascular alterations may be the decisive criterion for disease activity, with rapid dynamics of capillaroscopic findings considered an indicator of active disease 4. Vascular recovery has been observed after treatment with immunosuppressive drugs, hematopoietic stem cell transplantation, and endothelin receptor antagonists like bosentan 4.

Common pitfall: Do not rely solely on capillaroscopy pattern to predict specific organ involvement, as the phase changes are not specific for certain clinical manifestations. Instead, use the rate of capillary loss and pattern evolution to assess overall disease activity and progression risk. 4, 6