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Facial Rosacea:
Vascular Basis of the Disorder
I.
Introduction
II. Normal Blood
Vessels
o
- Function of normal blood vessels
- Structure of normal blood vessels
III. Rosacea Blood
Vessels
o
- Rosacea blood vessels undergo changes in function
- Rosacea blood vessels undergo changes in structure
IV. Summary of Functional
and Structural Changes
V. References
I. Introduction
Rosacea is primarily a
disorder of the facial blood vessels. Experts from across the world
agree that vascular abnormalities are central to all stages and
symptoms of rosacea:
- Dr. Ramelet states, "The skin alterations in all four
stages of rosacea as well as histopathologic investigations demonstrate
rosacea to be essentially a cutaneous vascular disorder."
(1)
- In a recent medical review article, "Rosacea: Pathophysiology
and Treatment", Dr. Wilkin stresses that rosacea is primarily
a disorder of the facial blood vessels. (2)
- A study performed by Dr. Marks on dozens of facial biopsies
indicates that all major rosacea symptoms such as facial erythema
(redness), telangiectasia (broken blood vessels), and inflammatory
papules are vascular in origin. (3)
- Dr. Wollina stresses, "The basic abnormality in rosacea
seems to be microcirculatory..... It is primarily a vascular disorder."
(4)
- Consistent with the above reports, numerous other medical researchers
emphasize that blood vessel abnormalities are key to the development
and progression of rosacea. (5-8)
Before discussing rosacea
abnormalities, the reader must first understand the function and
structure of normal blood vessels.
II. Normal Blood
Vessels
1. Function
of Normal Blood Vessels
The human facial skin
is densely supplied by blood vessels of different shapes and sizes.
In the facial skin, normal blood vessels serve several important
functions:
- Blood vessels deliver oxygen and essential nutrients
to the facial skin.
- Blood vessels remove waste products that are
generated from cells of the facial skin.
- Blood vessels help to regulate internal body
temperature. If internal body temperature gets too high it triggers
an increase in blood flow through the facial blood vessels.
This releases large amounts of heat from the skin surface and
helps decrease internal body temperature back down to normal
levels.
2. Structure
of Normal Blood Vessels
In all simplicity, blood
vessels are hollow tubes that serve as a highway system for the
delivery of substances to and from certain areas of the body.
The wall of an individual blood vessel is made up of several different
physical layers, with each layer serving a specific purpose. The
two most important layers of a vessel wall are the middle layer
(comprised of vascular smooth muscle cells), and the inner layer
(comprised of endothelial cells).
Vascular smooth muscle cells: This is the 'muscle'
of the blood vessel. The main function of this muscular layer
is to control blood flow:
Endothelial cells: Endothelial cells line the
inside of the blood vessel wall. They are in direct contact with
the flowing blood. These cells are important regulators of blood
vessel diameter. Endothelial cells normally release potent
dilator substances which diffuse to nearby smooth muscle cells
and cause the muscular layer to relax. This results in blood vessel
dilation and increased skin blood flow.
III. Rosacea
Blood Vessels
1. Rosacea Blood Vessels Undergo Changes in Function
Rosacea blood vessels
often experience changes in function. These blood vessels become
hyper-responsive to internal and external stimuli. Three
different functional changes may take place: (1) Rosacea blood
vessels may dilate to a substance that normal blood vessels do
not respond to at all, (2) Rosacea blood vessels may open up more
widely than normal blood vessels, and (3) Rosacea blood vessels
may stay open for abnormally long periods of time. In many rosacea
sufferers, all three of these changes take place. This hyper-responsiveness
lays the foundation for rosacea, resulting in increased blood
flow through the facial skin. (9 - 12)
2. Rosacea
Blood Vessels Undergo Changes in Structure
Clinical studies on
rosacea sufferers demonstrate that in addition to the above listed
functional changes, rosacea blood vessels may undergo extensive
structural changes. Experts stress that these changes are
ultimately responsible for the progression of all rosacea symptoms.
(7, 13) Structural changes may include:
- Permanent dilation of blood vessels (telangiectasia):
Clinical studies on rosacea sufferers demonstrate that a significant
portion of facial blood vessels are 'broken'; these vessels
are permanently fixed in a dilated state. (13-18)
- Damage to vascular smooth muscle: In rosacea
subjects, the muscular layer of facial blood vessels is often
found to be damaged and abnormally thin. (3, 14, 18-20)
- Damage to endothelial cells: In rosacea
sufferers, the inner layer of the blood vessel wall is often
found to be severely damaged and dysfunctional. (18, 21)
- Growth of new vessels: In addition to the
above structural changes, experts have found that abnormal growth
of new blood vessels may occur in rosacea sufferers. (2, 18,
22) This is called angiogenesis (an-gee-O-gen-esis).
- Orientation of blood vessels closer to the
surface of facial skin: Medical reports on rosacea sufferers
indicate that blood vessels may become oriented so that they
are closer to the surface of the facial skin. (23, 24)
- Fusion of blood vessels: In rosacea subjects,
abnormal fusion of damaged blood vessels may also occur. (18)
IV. Summary
of Functional and Structural Changes
As the reader now knows,
rosacea is primarily a facial vascular disorder in which the affected
blood vessels are functionally and structurally abnormal. In rosacea,
the functional changes usually occur first. Over time, this functional
hyper-responsiveness may then lead to blood vessel damage and subsequent
structural changes. This results in more blood flow through the
facial skin -- causing more inflammation and damage -- making the
condition worse. This is why rosacea is a chronic and progressive
disease; each vascular change feeds the underlying fire.
V. References
- Ramelet, A.A. Rosacea: a reaction pattern associated with ocular
lesions and migraine? Arch Dermatol 130: 1448, 1994.
- Wilkin, J.K. Rosacea. Pathophysiology and treatment. Arch
Dermatol 130: 359-362, 1994.
- Marks, R. Histogenesis of the inflammatory component of rosacea.
Proc R Soc Med 66: 742-745, 1973.
- Wollina, U. The response of erythematous rosacea to ondansetron.
Br J Dermatol 140: 561-562, 1999.
- Borrie, P. "The state of the blood vessels of the face
in rosacea - II". Br J Dermatol 67: 73-75, 1955.
- Brinnel, H., J. Friedel, M. Caputa, M. Cabanac, and E. Grosshans.
Rosacea: disturbed defense against brain overheating. Arch
Dermatol Res 281: 66-72, 1989.
- National Rosacea Society. "Rosacea Review". Spring.
1999. Drake,L.
- Marks, R. and J.N. Harcourt-Webster. Histopathology of rosacea.
Arch Dermatol 100: 683-691, 1969.
- Lowe, N.J., K.L. Behr, R. Fitzpatrick, M. Goldman, and J. Ruiz-Esparza.
Flash lamp pumped dye laser for rosacea-associated telangiectasia
and erythema. J Dermatol Surg Oncol 17: 522-525, 1991.
- Wiemer, D.R. Rhinophyma. Clin Plast Surg 14: 357-365,
1987.
- Elliott, R.A.J., L.E. Ruf, and J.G. Hoehn. Rhinophyma and its
treatment. Clin Plast Surg 7: 277-288, 1980.
- Thiboutot, D.M., P.C. Donshik, D.M. Hoss, and W.H. Ehlers.
Acne Rosacea: Inflammatory and papulo-squamous disorders of the
skin and eye. Am Fam Physician 50: 1691-1692, 1994.
- Balch, P. and J. Balch. "Rosacea". In: Prescription
for nutritional healing, 1999, p. 462-464.
- Wollina, U. Rhinophyma--unusual expression of simple-type keratins
and S100A in sebocytes and abundance of VIP receptor-positive
dermal cells. Histol Histopathol 11: 111-115, 1996.
- Applebaum, J. and J.S. Nelson. "Telangiectasia and miscellaneous
vascular lesions". In: Lasers in Plastic Surgery and Dermatology,
edited by B.M. Achauer, Vander KamV.M., and M.W. Berns. New York:
Thieme Medical Publishers, 1992, p. 70-91.
- Motley, R.J., S. Barton, and R. Marks. "The significance
of telangiectasia in rosacea". In: Proceedings of an International
Symposium, Cardiff, edited by R. Marks and G. Plewig. Cardiff:
Martin Dunitz Ltd, 1988, p. 339-344.
- Gratton, D. The many faces of rosacea. J Cutan Med Surg 2 Suppl
4: S4-S4, 1998.
- Neumann, E. and A. Frithz. Capillaropathy and capillaroneogenesis
in the pathogenesis of rosacea. Int J Dermatol 37: 263-266,
1998.
- Sobye, P. "Aetiology and pathogenesis of rosacea".
Acta Derm Venereol 30: 137-157, 1950.
- Delektorsky, V.V., L.S. Ananieva, A.M. Vavilov, and B. Ryzhkova.
"Nekotorye osobennostti ultrastruktury kapillyarnogo rusla
sosochkovogo sloya dermy u bolnykh eritematoznoy stadley rozatsea.".
Vestn Dermatol Venereol 5: 8, 1978.
- Nunzi, E., A. Rebora, F. Hamerlinck, and R.H. Cormane. Immunopathological
studies on rosacea. Br J Dermatol 103: 543-551, 1980.
- Pierard, G.E., C. Pierard-Franchimont, and C.M. Lapiere. Proliferation
and hyperplasia of vascular endothelium in human skin. Am J
Dermatopathol 7: 477-488, 1985
.
- Wilkin, J.K. "The red face: Flushing disorders".
Clin Dermatol 11: 211-223, 1993.
- National Rosacea Society. "Rosacea Review". Summer.
1998. Drake,L.
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