Defective barrier function accompanied by structural changes of psoriatic stratum corneum

Although barrier function of psoriatic skin is shown to be decreased by measuring transepidermal water loss (TEWL), few reports exist examining other physical skin properties and components including stratum corneum hydration, natural moisturizing factor (NMF), free fatty acids (FFA), β‐sheet and α‐helix ratio of structural protein(s), and sebum content. We compared the skin properties and components of normal, involved and uninvolved skin of psoriasis. Using a corneometer and attenuated total reflection‐infrared spectrometer, we measured TEWL, stratum corneum hydration, NMF, FFA, β/α ratio and sebum in psoriasis vulgaris patients and healthy controls. TEWL and β/α ratio of involved psoriatic skin were significantly increased compared with uninvolved skin and normal control skin. In contrast, stratum corneum hydration , NMF and FFA, but not sebum, are significantly decreased in the involved skin compared with uninvolved skin and normal skin. TEWL and stratum corneum hydration returned to the normal levels following clinical improvement of the lesion. Barrier function and hydration of psoriatic skin are defective and secondary structure in stratum corneum protein is altered in the involved psoriatic skin.     

Beneficial effects of the melanocortin analogue Nle4‐D‐Phe7‐α‐MSH in acne vulgaris

Background α‐Melanocyte‐stimulating hormone (α‐MSH) is a melanocortin peptide that increases skin pigmentation during ultraviolet light‐mediated tanning. As α‐MSH has been shown to possess anti‐inflammatory effects, we assessed the clinical potential of a superpotent α‐MSH analogue, afamelanotide (Nle⁴‐d ‐Phe⁷‐α‐MSH), in patients with acne vulgaris, the most common inflammatory skin disorder. Methods Afamelanotide (16 mg) was given in a phase II open‐label pilot study subcutaneously as a sustained‐release resorbable implant formulation to 3 patients with mild‐to‐moderate facial acne vulgaris. Evaluation included lesion count, adverse effects and patient‐reported outcome. Monitoring of laboratory parameters included differential blood counts, electrolytes, urine analysis, and liver and kidney function tests. Skin melanin density was measured by reflectance spectrophotometry. Results The total number as well as the number of inflammatory acne lesions declined in all patients 56 days after the first injection of afamelanotide. Life quality as measured by Dermatology Life Quality Index likewise improved in all 3 patients 56 days after the first injection of afamelanotide. There were no adverse effects except mild and short‐term fatigue in one patient. All patients experienced increased pigmentation especially on the face. Clinically relevant changes in laboratory parameters were not detected. Conclusions Afamelanotide appears to have anti‐inflammatory effects in patients with mild‐to‐moderate acne vulgaris. Future trials are needed to confirm the anti‐inflammatory action of this melanocortin analogue in patients with acne vulgaris.     

Accumulation of lipid peroxide in the content of comedones may be involved in the progression of comedogenesis and inflammatory changes in comedones

Background  Previous studies reported that lipid peroxide (LPO) caused by oxidation of sebum is associated with the progression of acne vulgaris, and that therapy with antioxidative ingredients is efficacious for treatment. In this study, we hypothesized that lipid accumulation in comedones induces progression of comedogenesis and inflammatory changes in comedones, and investigated the possible role of accumulated LPO in comedogenesis and its inflammatory changes.
Methods  We first sampled comedones and the stratum corneum from patients with acne vulgaris. The quantities of LPO, interleukin-1-alpha (IL-1α), and NF-kappa-B (NF-κB) in comedones and in the stratum corneum from each patient were measured for comparison. Next, comedones were sampled again from the same patients and classified into five groups: microcomedo (MC), noninflammatory open comedo (NIOC), noninflammatory closed comedo (NICC), inflammatory open comedo (IOC), and inflammatory closed comedo (ICC). We measured quantities of LPO in each group.
Results  The quantities of LPO, IL-1α, and NF-κB were significantly higher in the content of comedones than those in the stratum corneum. The quantities of LPO in the content of IOC and ICC were significantly higher than those of MC, NIOC, and NICC; however, there were no significant differences in quantities of LPO between the content of MC, NIOC, and NICC.
Conclusions  We conclude that the accumulation of a certain amount of LPO in the content of comedones may play an important role in the progression of comedogenesis and the excessive accumulation of LPO may be involved in inflammatory changes in comedones.     

Gut microbiota alterations in moderate to severe acne vulgaris patients

Acne vulgaris is a chronic inflammatory dermatosis affecting approximately 85% of adolescents. There are many factors contributing to the development of this ailment. A recent study indicated that gut microbiota takes part in the pathogenesis of acne. We aimed to investigate the link between acne vulgaris and gut microbiota. A total of 31 moderate to severe acne vulgaris patients and 31 healthy controls were enrolled. We collected their feces, and gut microbiota was evaluated by the hypervariable regions of 16S rRNA genes through high‐throughput sequencing. We identified links between acne vulgaris and changes of gut microbiota. At the phylum level, Actinobacteria (0.89% in acne patients and 2.84% in normal controls, P = 0.004) was decreased and Proteobacteria (8.35% in acne patients and 7.01% in normal controls, P = 0.031) was increased. At the genus level, Bifidobacterium, Butyricicoccus, Coprobacillus, Lactobacillus and Allobaculum were all decreased. The observed difference in genera between acne patients and healthy controls provides a new insight into the link between gut microbiota changes and acne vulgaris risk.     

Expression of human neutrophil proteins in acne vulgaris

Background In acne vulgaris patients, the presence of a dysregulation of the production of innate and specific antimicrobial peptides has been postulated. Objective This study aims to determine whether human neutrophil proteins (HNP) 1–3 are expressed in acne patients. Materials and methods HNP 1–3 expression was investigated in 35 acne patients treated with isotretinoin and in 25 healthy subjects. At the beginning of the study, two skin biopsies were taken from acne patients; one biopsy was taken from an established pustule and one from uninvolved skin, and the biopsies were repeated after treatment. Only one biopsy was obtained from controls. Results The statistical analysis showed that pustular lesions of acne patients had significantly higher levels of perivascular and interstitial HNP 1–3 expression when compared with the biopsy of uninvolved skin of these patients (P = 0.003, P = 0.001, respectively) and with that of healthy controls (P = 0.007, P = 0.014, respectively). Isotretinoin treatment achieved a decrease in the perivascular and interstitial HNP 1–3 expression of pustular lesions (P = 0.01, P = 0.001, respectively). Conclusion Our current study demonstrates the novel observation that a recently identified antimicrobial peptide, HNP 1–3, is expressed in neutrophils of acne inflammation but not in uninvolved skin of these patients. These results suggest that HNP 1–3 may contribute to the development of inflammatory lesions of acne.     

Skin microbiome differences relate to the grade of acne vulgaris

The skin microbiome plays important roles in the pathogenesis and development of acne. We aimed to investigate the facial skin microbiome of acne and microbiome differences related to different grades of acne. Skin swabs from nine healthy controls and 67 acne patients were collected, and the skin microbiomes were analyzed using 16S rRNA gene sequencing. Compared with healthy controls, acne patients harbored significantly altered skin microbiomes. The skin microbiomes of patients with grade 1–3 acne were similar, but patients with grade 4 acne showed a significantly different skin microbiome compared with grade 1–3 acne, including increased alpha diversity and increased proportions of four Gram‐negative bacteria (Faecalibacterium, Klebsiella, Odoribacter and Bacteroides). In conclusion, acne patients harbored an altered skin microbiome, and more significant dysbiosis was found in patients with grade 4 acne (severe acne). Our findings may provide evidence for the pathogenic mechanisms of acne and microbial‐based strategies to avoid and treat acne, especially grade 4 acne.     

Clinical significance of neutrophil gelatinase‐associated lipocalin and galectin‐7 in tape‐stripped stratum corneum of acne vulgaris

The usefulness of stratum corneum neutrophil gelatinase‐associated lipocalin and stratum corneum galectin‐7 as biomarkers of acne vulgaris was studied. A comparison of neutrophil gelatinase‐associated lipocalin levels on the cheeks of patients with acne vulgaris at the start of the study and at the time of symptom improvement showed a significant decrease. On the other hand, the galectin‐7 levels at the time of symptom improvement were significantly higher than those at the start of the study. Therefore, because the inflammation in the epidermis and hair follicles was reduced after therapy, as a result of the solution of the inflammatory eruptions caused by acne vulgaris, the neutrophil gelatinase‐associated lipocalin level also showed a significant decrease after therapy. These results suggest that stratum corneum neutrophil gelatinase‐associated lipocalin may be useful as an objective biomarker of changes in acne vulgaris symptoms.     

No evidence for follicular keratinocyte hyperproliferation in acne lesions as compared to autologous healthy hair follicles

Abnormal hyperkeratinization in sebaceous hair follicles has long been believed to play an important role in acne pathogenesis. Several early reports purported to provide histological evidence for hyperproliferation of keratinocytes in acne lesions by showing a higher expression of the Ki67 as well as certain keratins. The evidence is, however, not robust, and a number of methodological and technical limitations can be identified in these studies. In this study, we looked at the expression of proliferation, mitosis and apoptosis markers directly at acne skin lesions in 66 patients with acne vulgaris. Ki67 was assessed using immunohistochemistry and α‐tubulin, phospho‐histone H3 and cleaved‐PARP with immunofluorescence microscopy. Allogenic unaffected hair follicles from the same acne patients were used as an internal control. In both acne and control hair follicles, the α‐tubulin staining was universal, approaching 100% cells and showed no signs of changed assembly. Expression of cleaved‐PARP—the apoptosis marker—was a rare event. Cell proliferation rate measured by the expression of Ki67 and phospho‐histone H3 was virtually identical between acne and the two control groups. Our findings show the absence of increased keratinocyte proliferation in acne vulgaris. Alternative mechanisms are likely responsible for infundibular hyperkeratinization in acne pathogenesis.     

The correlation between ABO blood types and acne vulgaris severity

Background

Acne vulgaris is a chronic inflammatory disease with multifactorial etiology. Studies on the pathogenesis of acne are still important. Recently, various studies have been conducted on the significance of genetics in the pathogenesis of acne. Blood group is transferred genetically and could affect the development, progress, and severity of certain diseases.

Aim

In the current study, the correlation between the severity of acne vulgaris and ABO blood groups was investigated.

Materials and Methods

A total of 380 patients (263 mild and 117 severe acne vulgaris patients) and 1000 healthy individuals were included in the study. Severity of acne vulgaris patients and healthy controls was determined based on the blood group and Rh factor data obtained retrospectively from the patient files in the hospital automation system.

Results

In the study, the rate of females was significantly higher in the acne vulgaris group (X²:154.908; p:0.000). The mean age of the patient was significantly lower when compared to the controls (t:37.127; p:0.0001). The mean age of the patients with severe acne was significantly lower when compared to those with mild acne. When compared to the control group, the incidence of severe acne was higher in those A blood type when compared to the patients with mild acne, while the incidence of mild acne was higher in other blood groups when compared to the control (X²:17.756; p:0.007). No significant difference was determined between the Rh blood groups of the patients with mild, severe acne and the control group (X²:0.812; p:0.666).

Conclusion

The results revealed a significant correlation between acne severity and ABO blood groups. Future studies that would be conducted with larger samples in different centers could confirm the current study findings.     

Efficacy of the combined use of a facial cleanser and moisturizers for the care of mild acne patients with sensitive skin

Acne is a common skin disease that involves the seborrheic area of the face and results from the obstruction of hair follicles followed by inflammation. Careful face washing helps to improve and prevent acne; however, intensive washing has a risk of inducing skin barrier impairment and dry skin, especially in sensitive skin. We hypothesized that skin care combining mild skin cleansing and intensive moisturizing (“combination skin care”) may be effective in the care of acne in subjects with dry skin and/or sensitive skin. We developed a combination skin care with a weakly acidic foaming facial skin cleanser based on a mild detergent, an aqueous lotion with eucalyptus extract and a moisturizing gel containing pseudo‐ceramide and eucalyptus extract. To optimize an ideal facial skin care system for mild acne on sensitive skin, we performed a 4‐week clinical trial with 29 post‐adolescent Japanese women with mild acne with dry and sensitive skin. The acne significantly decreased after this trial accompanied by the improvement of dry skin, a significantly increased endogenous ceramide level in the stratum corneum and an elongated alkyl chain length of the non‐hydroxy acyl sphingosine type ceramide. No adverse events due to the test samples were observed. Based on diagnosis by a dermatologist, 97% of the subjects found the combination skin care to be “useful” or “slightly useful”. Based on these findings, the combined use of a facial skin cleanser and moisturizers is safe and effective for the care of acne in post‐adolescent Japanese women with sensitive skin.     

An assessment of the efficacy of blue light phototherapy in the treatment of acne vulgaris

Background Acne vulgaris is a common skin condition that affects 8 out of 10 people. It varies from mild to severe, and different treatments target various aspects of the disease. Propionibacterium acnes, one of the culprits involved in the pathogenesis of acne vulgaris, is the main target of all major medical treatments used. Studies conducted in recent years have shown favorable effects within the visible light spectrum for the treatment of acne vulgaris. Objective In this study, we have evaluated the use of intense blue light within the spectral range of 415–425 nm (peak 420 nm) in the treatment of acne vulgaris. Methods Twenty‐one patients with mild to moderate facial acne were treated with blue light phototherapy. All patients were given 14‐min treatment sessions twice a week for 4 weeks. Acne severity was assessed using the Leeds Technique for grading and lesion counts. Disability was assessed using the Dermatology Life Quality Index (DLQI). In addition, standard digital and cross‐polarized light photographs were taken and graded by a blinded evaluator. Visual analog scale (VAS) scores and cultures for P. acnes were carried out before starting the treatment and upon completion of the treatment. Results Significant improvement was achieved in the Leeds Acne Grade (P = 0.001). The inflammatory (P = 0.001) and noninflammatory (P = 0.06) lesion counts also improved significantly. A similar change was noted in the DLQI (P = 0.001); a degree of significance was also achieved in the patients’ and the investigators’ VAS scores (P = 0.01 and P = 0.001, respectively). P. acnes colony counts failed to show a significant decrease at the end of the treatment and remained almost constant (P = 0.660). Conclusions We believe that blue light does appear to have some role in the management of acne and may be beneficial for the treatment of a select group of mild to moderate acne patients.     

An observational study of methionine‐bound zinc with antioxidants for mild to moderate acne vulgaris

APC is a novel methionine‐based zinc complex with antioxidants that has been used in acne as a nutritional supplement. This is based on the proven role of zinc and antioxidants in improving acne, specially the inflammatory lesions. The objectives of this study are to explore the efficacy, safety, and tolerability of APC in acne patients with mild to moderate facial acne vulgaris. In this exploratory trial, 48 patients were treated with oral APC thrice a day for 3 months followed by a 4‐week treatment‐free period. At the end of treatment (Week 12), there was a statistically significant improvement in the global acne count (p < 0.05), which began after 8 weeks (p < 0.05). Almost 79% (38/48) of the patients had 80–100% improvement. There was a significant reduction in pustules (8 weeks (p < 0.05) and 12 weeks (p < 0.001)), and papules and closed comedones (8 weeks (p < 0.05) and 12 weeks (p < 0.001)). Only two patients had side effects. The current data indicate that treatment with oral APC thrice daily for 12 weeks in patients with mild to moderate facial acne vulgaris is efficacious and well tolerated. As the onset of action is late, concomitant topical therapy can enhance the results.     

Tissue and blood superoxide dismutase activities and malondialdehyde levels in different clinical severities of acne vulgaris

Background Acne vulgaris is one of the commonest dermatological diseases and its pathogenesis is multifactorial. Objectives To determine the role of oxidative stress in acne vulgaris and to determine a possible link with the clinical severity. Methods Twenty‐three patients with different grades of acne vulgaris and 23 age‐ and sex‐matched controls were enrolled. Superoxide dismutase (SOD) activities and malondialdehyde (MDA) levels were measured spectrophotometrically at tissue and blood levels. Results There were no significant differences in SOD activities and MDA levels between patients and controls. However, significant differences were found in patients with severe acne in comparison with those with mild and moderate acne. Moreover, comparison between different patient subgroups and controls revealed statistically significantly higher SOD activities in patients with mild acne in comparison with patients with moderate and severe acne, and with controls. Furthermore, severe acne showed statistically significantly lower SOD activities and higher MDA levels when compared with other patient subgroups and controls. Conclusions Oxidative stress exists in patients with acne vulgaris and may play a role in aetiopathogenesis and/or progression of the disease. The addition of drugs with antioxidative effects seems to be valuable in the treatment of acne vulgaris.     

Therapeutic efficacy of metronidazole by needle-free jet injection combined with blue light therapy in Moderate-to-Severe facial acne vulgaris

Background

Acne vulgaris is one of the most common dermatological diseases. Some topical treatments for acne used in combination, such as blue light and topical antibiotics (such as metronidazole) by needle-free jet injection (NFJI), are becoming prevalent in clinical practice, but the efficacy remains uncertain.

Methods

In order to investigate the effect of blue light combined with metronidazole by NFJI in the treatment of acne, the 251 enrolled patients were randomly assigned into the blue light group, metronidazole (MNZ) group, and MNZ + blue light group, and then received 6-weeks' treatment. A variety of objective and subjective methods such as clinical pictures, skin barrier physiological parameters (including trans-epidermal water loss (TEWL), stratum corneum hydration, facail surface sebum, erythema and pigmentation), the Investigator Global Assessment score, acne lesion count assessment, Patients' Self-Assessment, and VAS score were used to evaluate the efficacy and side effects of the treatments.

Results

Compared to the baseline, the MNZ + blue light group showed significant improvement in acne lesion count reduction, TEWL, straum corneum hydration, facial surface sebum and erythema (p < 0.05). The MNZ + blue light group showed significant differences compared with the MNZ group and blue light group in terms of acne lesion count reduction and erythema (p < 0.05) Compared to the MNZ group, the MNZ + blue light group demonstrated significant improvement in TEWL and sebum (p < 0.05). While compared to the blue light group, the MNZ + blue light group showed significant improvement in hydration (p < 0.05). There was no statistically significant difference among the three groups in pigmentation (p > 0.05).

Conclusion

The combination of MNZ by NFJI and blue light has a synergistic effect and can relieve acne skin lesion within 6 weeks in the treatment of moderate and moderate–to–severe facial acne vulgaris, meanwhile, this method has a good safety.     

The frequency of polycystic ovary syndrome in females with resistant acne vulgaris

Background Acne vulgaris in females may be resistant to treatment in spite of topical and systemic therapy for a sufficient period. In this condition, acne may be a manifestation of underlying endocrine conditions such as polycystic ovary syndrome (PCOS). Objective To evaluate the frequency of PCOS in females with resistant acne vulgaris. Patients and methods This case‐controlled study was conducted in the Department of Dermatology and Venereology in The Teaching Hospital in Al‐Najaf during the period from October 2007 to November 2008. One hundred and twenty‐three female patients with resistant acne vulgaris were included in this study. One hundred and twenty‐three women, age‐matched, without acne were enrolled as a control group. Detailed history, clinical examination, abdominal ultrasound study, and hormonal assays were obtained for the patients and the control group. Results One hundred and twenty‐three females with resistant acne were included; their ages ranged from 17 to 40 years with a mean of 25.016 ± 6.041 (SD). One hundred and twenty‐three control women without acne were enrolled; their ages ranged from 17–40 years with a mean of 26.014 ± 6.251 (SD). The patients and the control group are age‐matched (P = 0.192). It was found that 63 patients (51.2%) with resistant acne have PCOS in comparison to only eight control women (6.2%). The difference is highly significant. Conclusion Polycystic ovary syndrome is an important contributing factor in females with resistant acne vulgaris.     

Ceramide profiles of the uninvolved skin in atopic dermatitis and psoriasis are comparable to those of healthy skin

Ceramides are sphingolipids consisting of sphingoidbases, which are amide-linked to fatty acids. In the stratum corneum, they represent the major constituent of the free extractable intercellular lipids and play a significant role in maintaining and structuring the water permeability barrier of the skin. Using thin layer chromatography, which represents the method of the first choice in analyzing the stratum corneum ceramides, at least seven classes can be distinguished. Each ceramide class contains various species, which have the same head group and different chain lengths. As in many other skin disorders, atopic dermatitis and psoriasis show derangements in content and profile of the ceramides. Such derangements were reported for both the lesional involved as well as for the normal-appearing uninvolved skin. In this study, we focused on investigating the stratum corneum ceramides of the uninvolved skin in atopic dermatitis and psoriasis patients compared to healthy skin. The aim of the investigations was to explore possible significant and specific differences which can be accomplished for purposes of early diagnostics. The skin lipids were collected by means of an in vivo topical extraction procedure using an extraction mixture consisting of n-hexane and ethanol, (2:1). An automated multiple development-high performance thin layer chromatography (AMD-HPTLC) method with photodensitometric detection were applied to separate the ceramides and to estimate their contents. For studying their molecular profile within each ceramide class, a new method of normal phase HPLC with atmospheric pressure chemical ionization mass spectrometry were used. The results obtained by AMD-HPTLC exposed no significant alterations regarding the relative composition of the major stratum corneum lipids and primarily the ceramides. In addition, the mass spectrometric profiles within each ceramide class were similar in the patients and the healthy control subjects. In conclusion, this study revealed that the normal-appearing uninvolved skin of atopic dermatitis and psoriasis patients does not prove significant or specific deficiencies with respect to the free extractable major stratum corneum lipids and mainly the ceramides, when compared to healthy skin. Thus, they cannot be used for diagnostic purposes. Furthermore, our data are not consistent with the concept that impairments in the ceramide composition represent an obligate etiologic factor for both diseases.     

Plasma dermcidin levels in acne patients,and the effect of isotretinoin treatment on dermcidin levels

Acne vulgaris is a chronic inflammatory disease of the pilosebaceous unit. Dermcidin (DCD) is an antimicrobial peptide released from eccrine sweat glands and sebaceous glands. Studies investigating the role of DCD expression in acne development are scarce. The aim of this study was to determine the relationship between DCD expression and acne vulgaris and the effect of oral isotretinoin treatment on DCD levels. Two groups (one patient group and one control group) were included in the study. The patient group consisted of 30 patients with acne vulgaris who were given oral isotretinoin treatment for 6 months until the cumulative dose was attained. Plasma DCD levels were investigated before and 6 months after treatment. The control group comprised 30 volunteer individuals without acne vulgaris or any inflammatory dermatosis. Of the patients, 24 (80%) had Grade 3, 3 (10%) had Grade 1, and 3 (10%) had Grade 4 acne vulgaris, as determined according to the Pillsbury scoring method. The DCD levels in the control group were significantly higher than those in pretreatment patients (39.53 ± 20.2 vs. 28.60 ± 20.12, p = .004). Additionally, pretreatment DCD levels were significantly increased after 6 months of isotretinoin treatment in the patient group (28.60 ± 20.12 vs. 35.07 ± 24.02, p = .012). The mean pretreatment global acne grading system score of 20.86 ± 4.43 was decreased to 5.17 ± 1.91 in patients after treatment (p < .001). This study indicated that DCD plays an important role in the pathogenesis of acne. It demonstrates anti‐inflammatory properties in acne vulgaris. Moreover, it was shown that isotretinoin treatment may improve acne vulgaris by increasing DCD levels.     

The role of the antioxidative defense system in papulopustular acne

Acne vulgaris frequently occurs in the second decade of life. The pathogenesis of the disease is multifactorial. In this study, we aimed to investigate the role of reactive oxygen species in inflammation of acne by determining the activity of antioxidant defense enzymes in leukocytes. Fifty-two patients with papulopustular type acne vulgaris and 36 healthy controls were enrolled. The severity of the disease was examined by the Global Acne Grading System, and the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) enzymes as well as the level of thiobarbituric acid reactive substance (TBARS) were detected in leukocytes. The activities of SOD and GSH-Px were significantly decreased in the acne group. CAT activity and TBARS level were higher in patients than controls. Only a poor correlation was detected between GSH-Px activity and severity of the disease. Antioxidative defense enzymes are impaired in papulopustular acne, and drugs with antioxidative effects might be valuable in treatment.     

The familial risk of acne vulgaris in Chinese Hans – a case-control study

BACKGROUND: Acne is a chronic inflammatory disease of the pilosebaceous follicles. Recent studies bring us increasing evidences that hereditary factors play an important but indirect role in acne. OBJECTIVE: To investigate the possible role of genetic factors in the pathogenesis of acne vulgaris in Chinese Han ethnic group. PATIENTS AND METHODS: Volunteers of 975 acne cases and 580 controls were included, contributing 3009 and 1825 first-degree relatives, respectively. One thousand and eighty-five first-degree relatives of acne cases were affected with facial acne. This compared with 223 first-degree relatives of non-acne controls. The odds ratio was used to estimate the relative risk for acne vulgaris associated with having an affected first-degree relative. RESULTS: The risk of acne vulgaris occurring in a relative of a patient with acne vulgaris was significantly greater than for the relative of an unaffected individual (odds ratio 4.05, 95% confidence interval (CI): 3.45-4.76, P<0.001). CONCLUSION: Our study suggests that familial factors are important in determining individual susceptibility to acne vulgaris.