The small blood vessels of the skin in acrocyanosis. Comparison of biomicroscopy and biopsy findings

Acral coldness - severely reduced blood flow to fingers and toes

The term acral coldness is used to describe physiologic or pathologic situations in humans where the fingers and toes are exceptionally cold in spite of normal central body temperature. In the thermoneutral zone, the blood flow to acral skin normally shows large fluctuations between high and low values, with a frequency of about 3 cycles per minute. At an acral skin temperature of about 21°C, finger blood flow is constantly low. At lower temperatures the fingers and toes become painful. This is a normal physiologic reaction, probably because of ischemia. The characteristics of the most frequent acral vascular syndromes, Raynaud phenomenon, acrocyanosis, and chilblains, are discussed. Common to all three is pathologically low blood flow and disappearance of physiologic fluctuations even in the thermoneutral zone. Ischemic vascular diseases in acral skin are usually diagnosed from clinical observations. Measurements of fluctuating blood flow by laser or ultrasound Doppler could be useful, but should be carried out at a room temperature of 24-25°C.

Acrocyanosis: the Flying Dutchman

Acrocyanosis is symmetric, painless, discoloration of different shades of blue in the distal parts of the body that is marked by symmetry, relative persistence of the skin color changes with aggravation by cold exposure, and frequent association with local hyperhidrosis of hands and feet. Described over a century ago and despite seeming familiarity, it remains a poorly understood condition that shares much in clinical presentation with other conditions characterized by skin color changes in the distal parts of the body. The diagnosis remains mostly clinical, and pathological mechanisms vary suggesting that acrocyanosis may not be a single entity. We performed an extensive literature review to summarize existing knowledge about the demographics, pathology, diagnosis, and treatment of this condition.

Quantitative nailfold capillary microscopy findings in patients with acrocyanosis compared with patients having systemic sclerosis and control subjects

BACKGROUND

The morphologic capillary microscopy (capillaroscopy) pattern of acrocyanosis is characterized by hemorrhages, pericapillary edema, and widened capillaries. These findings can result in a difficult differential diagnosis with systemic sclerosis (SSc).

OBJECTIVE

We sought to quantify the characteristics of the capillaroscopy pattern that distinguishes patients with acrocyanosis from patients with SSc and control subjects.

METHODS

A videomicroscope with fiberoptic illumination and personal computer-based image processing was used to measure capillary density, giant capillaries, loop width, and arterial and venous limbs in 10 patients with acrocyanosis, 10 patients with SSc, and 10 healthy control subjects.

RESULTS

Acrocyanotic patients differed in every quantitative parameter both from control subjects and patients with SSc. In particular, capillary density, which was reduced compared with that of control subjects, was much higher than that of patients with SSc: one giant capillary per finger was observed in 2 patients with acrocyanosis, whereas more than 2 giant capillaries per finger were observed in each patient with SSc.

CONCLUSION

These differences may aid in making the distinction between the capillaroscopy patterns in acrocyanosis and SSc.

Histopathological and capillaroscopical features of the cuticles and bleeding clots in ring or middle fingers of systemic scleroderma patients

Sixty-three patients with systemic scleroderma (SSc) (Barnett I, 41; Barnett II, 17; Barnett III, 5), 14 with systemic lupus erythematosus (SLE), 9 with dermatomyositis (DM) and 10 healthy controls (HC) were subjected to histopathological examinations of the cuticles of ring or middle fingers. The sex ratios (male/female) in the patients with SSc, SLE, DM and HC were 7:56, 5:9, 5:4 and 5:5, and the ages were 22-74, 19-78, 45-70 and 13-78 years old, respectively. Biopsy samples were taken from the central portion of the cuticles, which showed the most severe change of elongation with or without bleeding clots of cuticle-proximal nailfolds (BC). Histopathologically, 61 (96.8%) cuticles of SSc patients consisted of the upper (U), middle (M) and lower (L) layers, which represent obliquely stacked, parabolic, and parallel stacked layers, respectively. The middle parabolic layer appeared to discharge homogenous eosinophilic globular deposits (ED). On the other hand, this typical three-layer-nail pattern was seen only in 9 (64.3%) of SLE, 3 (33.3%) of DM and none of HC, in total 12 (36.4%) of the non-SSc group, which included SLE, DM and HC. In SSc, there were statistical correlations (R2) between ED and BC, ED and cuticle-elongation, cuticle-layer and cuticle-elongation, ED and cuticle-layer, BC and cuticle-elongation. Capillaroscopically, bleeding clots located in the middle layer with ED of the cuticles in eight patients with SSc were transported rapidly within 1-2 weeks.(ABSTRACT TRUNCATED AT 250 WORDS)