Published 8 July 2026 at 20:20
A rheumatologist at Karolinska University Hospital has a patient in front of them: a woman in her mid-thirties who has had cold fingers and blue fingertips for the past two years. Clinically, Raynaud’s phenomenon is confirmed. The question that determines the rest of her life is whether this is PRIMARY Raynaud’s (benign, no increased risk) or SECONDARY Raynaud’s (the first sign of systemic sclerosis, an autoimmune disease that, untreated, shortens life expectancy by 15-20 years). Her blood tests are normal. ANA antibodies are below the detection limit. All systemic markers point to ”no disease”. But the rheumatologist picks up their CapillaryScope 500 Pro, asks the patient to place her hand on the table, and studies the nailfold for three minutes. The diagnosis is made.
What they see in the microscope
In healthy capillary architecture, the capillaries lie as even, U-shaped loops in rows along the nailfold. In incipient secondary Raynaud’s/sclerosis, the picture looks completely different: enlarged ”giant capillaries” with 2-5 times the normal diameter, loss of some capillaries (drop-out), microhemorrhages (red dots between the vessels), and tree-like (bushy) branching where the normal U shape would have been. Rheumatology has a name for these changes: the ”sclerodermic pattern”. Its prevalence among patients with isolated Raynaud’s phenomenon is about 20%, and 90% of patients who show a sclerodermic pattern develop systemic sclerosis within 10 years.
Why the nailfold is the perfect place to observe
Capillaries are found everywhere in the body: skin, muscles, organs. Why the nailfold in particular? Two anatomical features: (1) the capillaries there run parallel to the skin surface rather than perpendicular to it, so they can be observed along their entire length; and (2) the skin is extremely thin (0.1-0.3 mm) and almost transparent under the nail. No other place in the body gives such clear, direct observation of the microcirculation without an invasive procedure.
The technique was first described by Otto Müller in 1918 in Germany, but it did not become a clinical standard until the 1970s, when Maricq and LeRoy published their classification criteria. Today, NVC (nailfold videocapillaroscopy) is part of the EULAR/ACR criteria for diagnosing systemic sclerosis.
What the CapillaryScope 500 Pro Wireless is
The Dino-Lite MEDLW4N5 Pro is a handheld digital microscope designed specifically for nailfold capillaroscopy. It offers 500× magnification, a 5-megapixel sensor, a built-in polarizer (to eliminate glare from the contact oil on the cuticle), and both USB and wireless WiFi connectivity for direct transfer to a PC or tablet. It is CE marked under the Medical Device Regulation (EU) 2017/745, meaning it is approved for clinical use on patients, not just as a lab instrument.
In practice: the rheumatologist applies a drop of immersion oil to the patient’s nailfold (which increases optical contrast), places the CapillaryScope head against the finger, and sees the image on the tablet screen immediately. The examination takes 3-5 minutes per patient, including all 10 fingers. Images are saved in the patient record with a timestamp.
Why wireless, and why wireless matters clinically
The clinical environment has a constraint that the lab environment does not: the patient has to be part of the measurement. A wireless device allows the rheumatologist to move the CapillaryScope across all 10 fingers without a cable pulling on the sensor head. The patient can keep their hand in a comfortable position instead of reaching toward a cable-tethered device. The image is streamed to the PC or tablet on the desk.
The practical consequence is that the examination can be done in any position: with the patient sitting or lying down, with the hand on the table, or with the hand resting in their lap. For patients with rheumatic pain, comfort during the examination is far from unimportant.
Other clinical applications
Although nailfold capillaroscopy is the core application, there are others:
- Dermatology: Melanoma diagnostics (dermatoscopy at 100-500×), inflammatory skin diseases (psoriasis), and infection diagnostics (fungus, parasites).
- Clinical microbiology: Staining of bacterial samples and mold identification.
- Hospital education: Students can see the same image as their supervisor on a shared screen, which is critical for remote supervision and remote consultation.
- Hair and scalp diagnostics: Alopecia type (androgenetic vs. cicatricial) and hair shaft defects.
Certification, and what it costs NOT to have it
MDR certification (EU 2017/745) is not the same as CE marking for consumer electronics. To be used in clinical practice on patients in the EU, a device must comply with the MDR, including technical documentation, clinical evaluation, post-market surveillance, and notified body review. A Dino-Lite USB microscope without MDR certification cannot legally be used for patient diagnostics, even though it physically does exactly the same thing.
The MEDLW4N5 Pro with MDR certification is the legally compliant version. Hospitals and clinics that purchase it, including the documentation, can integrate it directly into their QMS process.
What you get for your money
The Dino-Lite CapillaryScope 500 Pro Wireless costs SEK 11,712 and includes MDR certification, a 5 MP sensor, a built-in polarizer, wireless and USB connectivity, and all software. Compared with analog clinical-standard capillary microscopes (SEK 30,000-80,000, no digital storage), it costs roughly one third as much, and digital documentation is included.
The investment is reasonable for any rheumatology clinic that investigates patients with Raynaud’s. A single confirmed early diagnosis of systemic sclerosis affects the patient’s prognosis so dramatically that the cost of the instrument is negligible in context.
Read more: Dino-Lite CapillaryScope 500 Pro Wireless in the shop →
