Investigation of microvascular pathologies in psoriasis patients with capillaroscopy

Psoriasis is a chronic inflammatory disease that is characterized by hyperproliferation of keratinocytes, immune-mediated inflammation, and dysregulation of angiogenesis. It is thought that chronic systemic inflammation in psoriasis patients can induce both macrovascular atherosclerosis and microvascular changes. Microvascular changes in the nail bed have been studied by capillaroscopy in a small number of studies. The data from these studies are limited, and the association of microvascular changes with psoriasis comorbidities has not been investigated. The aim of this study was to systematically investigate the capillary patterns of psoriasis patients and to investigate the association of the observed patterns with disease characteristics, disease activity/duration, nail involvement, psoriatic arthritis and potential psoriasis comorbidities. This study included 67 psoriasis patients and 68 healthy controls. Demographic data of the patients and controls were collected. Eight images were taken from each of the fingers excluding the thumb using a Dino-lite Edge digital videocapillaroscope with 200x magnification. Capillary density, capillary density score, capillary distribution, capillary morphology, capillary pattern, microhemorrhages, avascular areas, and neovascularization were assessed. Capillary density was calculated by counting the number of capillaries in a 1-mm area in the distal row of the capillary array in each finger nail fold and taking the arithmetic mean. Capillary density score was scored according to the observed capillary density for each finger being assessed (0 point = >9 capillaries/mm, 1 point = 7-9 capillaries/mm, 2 points = 4-6 capillaries/mm, 3 points = <4 capillaries/mm). The effect of disease duration, severity, involvement, and psoriasis comorbidities on capillaroscopic findings was investigated. The study included 32 women and 35 men with psoriasis, and 35 women and 33 men in the control group, for a total of 135 participants. The mean age of the psoriasis group was 43.15±13.95 years, and the mean age of the control group was 41.81±12.49 years. There was no significant difference between the psoriasis and control groups in terms of age and gender. Thirteen of the psoriasis patients had psoriatic arthritis, and 28 had nail involvement. The mean nail bed capillary density was 8.06±0.95 in psoriasis patients, 7.85±0.86 in those with psoriatic arthritis, 8.095±0.99 in those with nail involvement, and 9.65±1.00 in the control group. All three groups had reduced capillary density compared to the control group. Avascular areas, neovascularization, and microhemorrhages were statistically significantly higher in psoriasis patients. Seventeen point six (17.6%) of psoriasis patients had a normal capillaroscopic pattern, while 82.4% had a nonspecific capillaroscopic pattern. The scleroderma pattern was not detected in any patient. Minor (tortuosity, crossing, elongation, and dilated capillaries) and major (meandering, bushy, and branched capillaries) morphological changes were more common in the psoriasis group. No association was found between disease severity and duration and capillaroscopic changes. When the association between psoriasis comorbidities and capillaroscopic findings was investigated, increased dilated capillaries were found in diabetic patients, and increased elongated capillaries were found in hypertensive patients. No association was found between metabolic syndrome and capillaroscopic findings. Psoriasis patients compared to the control group had reduced capillary density with increased capillary irregularity, avascular areas, neovascularization, microhemorrhages, dilated capillaries, bushy capillaries, branched capillaries, and meandering capillaries. These findings suggest increased microvascular damage in psoriasis. Large-scale prospective cohort studies are needed to evaluate nail bed capillary findings in psoriasis patientsand to investigate the association of these findings with disease activity, duration, and psoriasis comorbidities. Keywords: Psoriasis, Capillaroscopy, Angiogenesis, Microvascular damage