Epidermal hydration levels in patients with rosacea improve after minocycline therapy.

BACKGROUND: Patients with rosacea frequently report increased skin sensitivity, with features suggestive of an abnormal stratum corneum (SC) permeability barrier. Sebum, pH and hydration levels influence epidermal homeostasis. The correlation of changes in these parameters with clinically effective treatment has not been previously analysed. OBJECTIVES: To analyse sebum, pH and epidermal hydration levels of patients with papulopustular rosacea (PPR) before and after treatment with systemic minocycline. METHODS: We analysed sebum casual levels, pH and hydration along with erythema levels (as a marker of disease activity and response to treatment) on seven designated facial sites of 35 patients with active PPR and compared the results with values on the same sites of 34 control subjects with normal facial skin. To determine the effect of minocycline on these parameters, we re-examined the patients with PPR at the same sites after a 6-week course of treatment. RESULTS: Patients with untreated PPR had significantly increased erythema indices, normal sebum casual levels, a more alkaline centrofacial region and reduced epidermal hydration levels compared with controls. Treatment with minocycline resulted in reduced erythema and increased hydration levels, with the most marked changes evident in the cheeks (13·3% reduction in erythema indices, P < 0·001; 12·4% increase in hydration levels, P = 0·012). There was no change in skin pH or sebum casual levels following treatment. CONCLUSION: Patients with PPR have increased erythema indices, normal sebum casual levels, a more alkaline centrofacial region and reduced epidermal hydration levels compared with control subjects. Treatment with systemic minocycline reduces erythema and increases hydration, in the absence of any change in skin pH or sebum casual levels.

The fatty acid profile of the skin surface lipid layer in papulopustular rosacea.

BACKGROUND: Patients with papulopustular rosacea (PPR) frequently complain of dry, sensitive skin. We have previously demonstrated that patients with PPR have reduced skin surface hydration levels in the presence of normal sebum casual levels, suggesting that it may be the quality and not the quantity of sebum that plays a role in PPR. OBJECTIVES: To compare the sebaceous fatty acid composition of patients with PPR to that of controls with normal facial skin. METHODS: The sebaceous fatty acid composition of 25 patients with PPR and 24 age- and sex-matched controls was analysed by gas chromatography - mass spectrometry. Results Myristic acid (C14:0) was present in greater concentrations in PPR sebum, while the long chain saturated fatty acids arachidic acid (C20:0), behenic acid (C22:0), tricosanoic acid (C23:0) and lignoceric acid (C24:0) as well as the monounsaturated fatty acid cis-11-eicosanoic acid (C20:1) were present in the sebum of patients with PPR in lesser concentrations as compared with controls. CONCLUSIONS: There is increasing evidence that sebaceous fatty acids play a role in the maintenance of skin barrier integrity. We have shown for the first time that patients with PPR have an abnormal sebaceous fatty acid composition, with reduced levels of long chain saturated fatty acids. These new findings may have therapeutic implications for the development of sebum-modifying nonantibiotic treatments for patients with PPR.