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The William J. Cunliffe Lectureship 2003 –
Manuscript
Albert M. Kligman, M.D., Ph.D.
University of Pennsylvania, Philadelphia, Pennsylvania, U.S.A.
Perhaps the most notable feature of the abundant literature on rosacea is the abundance of controversies which relate to its clinical characterization and etiology.
Our ignorance about this chronic, distressing disorder, which mainly affects women is scandalous, an embarrassment that should make dermatologists as red-faced as their patients. While a new system of classification has been proposed, there are still deep disagreements about nosologic criteria.
The literature mainly consists of reports by reputable clinicians with a special interest in rosacea whose observations generally do not include the use of scientific methodologies that would qualify as evidence based medicine. For a specialty so finely focused on visualization, most published photographs are of exceedingly poor quality.
Treatment strategies are based more on the highly touted art of medicine rather than on the objective measurements that give scientific investigation its credibility.
The objective of our research over the past six years has been to develop non-invasive imaging and bioengineering techniques to obtain quantitative, objective information regarding putative etiologic factors which underlie pathogenesis and to establish evidence based criteria for assessing the efficacy of oral and topical therapies.
To this end we had modest success in developing methods for investigating various aspects of this multifarious disease which all agree is multifactorial in origin.
These include:
- Digital polarized light photography to show the intensity and distribution of erythema.
- High resolution (Hi-Scope) color, polarized light photos to assess telangiectatic pattern.
- One hour collection of sebum using Sebutapes to measure quantitatively the amount of sebum produced and the density and size distribution of sebum droplets. Sebum production is increased in rosacea patients compared to age-matched controls.
- Density of the anaerobic P. acnes population using the detergent scrub method. The quantity of P. acnes is increased in rosacea compared to age-matched controls.
- Cyanoacrylate follicular biopsies which show that rosacea patients have an increased number of microcomedones, populated by dense columns of P. acnes, which apparently are precursors of inflammatory papulo-pustules.
- Cyanoacrylate follicular biopsies also show that the density of the mite Demodex folliculorum is increased in rosacea and probably plays a contributing role in making rosacea skin hyper-irritable to physical and chemical insults.
- We have found that 500 mg of niacin orally induces an erythema in rosacea patients which appears more rapidly, reaches a greater peak intensity and lasts longer than controls. This sequence can be monitored quantitatively by Laser-Doppler color imaging and the calculation of perfusion units, showing markedly increased blood flow. It is of great interest that aspirin and other non-steroidal anti-inflammatory agents can block this erythema, even in low doses.
- We have developed a model for the local induction of erythema using methyl nicotinate, which distinguishes rosacea from controls. The potential importance of this model is that it can be used to assess objectively the efficacy of effective therapies such as oral tetracyclines.
These and other models and methods will be illustrated in the lecture. We believe that these sophisticated methods will enable us to investigate causation factors in the pathogenesis of rosacea and to establish stricter criteria for assessing efficacy of oral and topical treatments.
 | A Personal Critique on the State of Knowledge of Rosacea (PDF, 34 KB) |
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