Expression profiles of cortisol‐inactivating enzyme, 11β‐hydroxysteroid dehydrogenase‐2, in human epidermal tumors and its role in keratinocyte proliferation

The enzyme 11β‐hydroxysteroid dehydrogenase (11β‐HSD) catalyzes the interconversion between hormonally active cortisol and inactive cortisone within cells. There are two isozymes: 11β‐HSD1 activates cortisol from cortisone and 11β‐HSD2 inactivates cortisol to cortisone. 11β‐HSD1 was recently discovered in skin, and we subsequently found that the enzyme negatively regulates keratinocyte proliferation. We verified 11β‐HSD1 and 11β‐HSD2 expression in benign and malignant skin tumors and investigated the role of 11β‐HSD in skin tumor pathogenesis. Randomly selected formalin‐fixed sections of skin lesions of seborrheic keratosis (SK), squamous cell carcinoma (SCC), and basal cell carcinoma (BCC) were stained with 11β‐HSD1 and 11β‐HSD2 antibodies, and 11β‐HSD expression was also evaluated in murine epidermis in which hyperproliferation was induced by 12‐O‐tetradecanoylphorbol‐13 acetate (TPA). We observed that 11β‐HSD1 expression was decreased in all SK, SCC, and BCC lesions compared with unaffected skin. Conversely, 11β‐HSD2 expression was increased in SK and BCC but not in SCC. Overexpression of 11β‐HSD2 in keratinocytes increased cell proliferation. In the murine model, 11β‐HSD1 expression was decreased in TPA‐treated hyperproliferative skin. Our findings suggest that 11β‐HSD1 expression is decreased in keratinocyte proliferative conditions, and 11β‐HSD2 expression is increased in basal cell proliferating conditions, such as BCC and SK. Assessing 11β‐HSD1 and 11β‐HSD2 expression could be a useful tool for diagnosing and characterizing skin tumors.     

UVB induces epidermal 11β‐hydroxysteroid dehydrogenase type 1 activity in vivo

Detrimental consequences of ultraviolet radiation (UVR) in skin include photoageing, immunosuppression and photocarcinogenesis, processes also significantly regulated by local glucocorticoid (GC) availability. In man, the enzyme 11β‐hydroxysteroid dehydrogenase type 1 (11β‐HSD1) generates the active GC cortisol from cortisone (or corticosterone from 11‐dehydrocorticosterone in rodents). 11β‐HSD1 oxo‐reductase activity requires the cofactor NADPH, generated by hexose‐6‐phosphate dehydrogenase. We previously demonstrated increased 11β‐HSD1 levels in skin obtained from photoexposed versus photoprotected anatomical regions. However, the direct effect of UVR on 11β‐HSD1 expression remains to be elucidated. To investigate the cutaneous regulation of 11β‐HSD1 following UVR in vivo, the dorsal skin of female SKH1 mice was irradiated with 50, 100, 200 and 400 mJ/cm² UVB. Measurement of transepidermal water loss, 11β‐HSD1 activity, mRNA/protein expression and histological studies was taken at 1, 3 and 7 days postexposure. 11β‐HSD1 and hexose‐6‐phosphate dehydrogenase mRNA expression peaked 1 day postexposure to 400 mJ/cm² UVB before subsequently declining (days 3 and 7). Corresponding increases in 11β‐HSD1 protein and enzyme activity were observed 3 days postexposure coinciding with reduced GC receptor mRNA expression. Immunofluorescence studies revealed 11β‐HSD1 localization to hyperproliferative epidermal keratinocytes in UVB‐exposed skin. 11β‐HSD1 expression and activity were also induced by 200 and 100 (but not 50) mJ/cm² UVB and correlated with increased transepidermal water loss (indicative of barrier disruption). UVB‐induced 11β‐HSD1 activation represents a novel mechanism that may contribute to the regulation of cutaneous responses to UVR exposure.     

Effects of a ceramide‐containing water‐in‐oil ointment on skin barrier function and allergen penetration in an IL‐31 treated 3D model of the disrupted skin barrier

Atopic dermatitis (AD) is a chronically relapsing, pruritic inflammation of the skin with dryness and disturbed skin barrier function. Recently, we established that IL‐31 treatment of human 3D skin models resulted in a disrupted skin barrier phenotype resembling AD. In this model, we found that IL‐31 interferes with the differentiation of keratinocytes and inhibits the expression of terminal differentiation markers. In the present study, we investigated the effects of a ceramide‐containing water‐in‐oil skin care ointment on the physical skin barrier structure and function in disrupted skin barrier models, generated either by using primary normal human epidermal keratinocytes (NHEK) or HaCaT cells. We observed that the physical skin barrier of the models recovered after daily topical treatment with the ceramide‐containing ointment. Topical application of the ointment prevented downregulation of filaggrin and disorganization of other differentiation markers, such as keratin 10 and β4‐integrin, as demonstrated by immunohistological analysis. The expression of Ki67 was also upregulated in response to the ointment. Furthermore, functional studies revealed that local application of the ointment diminished the increased uptake of fluorescently labelled recombinant allergens of timothy grass (phl p1) in our model. In conclusion, our data revealed that topical application of a ceramide‐containing skin care ointment reduced IL‐31 induced impairments of the physical skin barrier and skin barrier function in an in vitro model of the disrupted skin barrier. This standardized model can be utilized in the future to monitor ex vivo effects of various topical therapies on skin morphology, physiology, and gene expression.     

1‐(2‐Hydroxyethyl)‐2‐imidazolidinone,a heparanase and matrix metalloproteinase inhibitor,improves epidermal basement membrane structure and epidermal barrier function

Daily exposure to sunlight is known to affect the structure and function of the epidermal basement membrane (BM), as well as epidermal differentiation and epidermal barrier function. The aim of this study is to clarify whether the inhibition of BM‐degrading enzymes such as heparanase and matrix metalloproteinase 9 (MMP‐9) can improve the epidermal barrier function of facial skin, which is exposed to the sun on a daily basis. 1‐(2‐hydroxyethyl)‐2‐imidazolidinone (HEI) was synthesized as an inhibitor of both heparanase and MMP‐9. HEI inhibited not only the BM damage at the DEJ but also epidermal proliferation, differentiation, water contents and transepidermal water loss abnormalities resulting from ultraviolet B (UVB). This was determined in this study by the use of UVB‐induced human cultured skins as compared with the control without HEI. Moreover, topical application of HEI improved epidermal barrier function by increasing water content and decreasing transepidermal water loss in daily sun‐exposed facial skin as compared with non‐treated skins. These results suggest that the inhibition of both heparanase and MMP‐9 is an effective way to care for regularly sun‐exposed facial skin by protecting the BM from damage.     

Side‐effects of henna and semi‐permanent ‘black henna’ tattoos: a full review

Henna, the dried and powdered leaf of Lawsonia inermis, is widely used as a dye for the skin, hair, and nails, and as an expression of body art, especially in Islamic and Hindu cultures. As it stains the skin reddish‐brown, it is also called red henna. Black henna is the combination of red henna with p‐phenylenediamine (PPD), and is used for temporary ‘black henna tattoos’. This article provides a full review of the side‐effects of topical application of red and black henna, both cutaneous (allergic and non‐allergic) and systemic. Red henna appears to be generally safe, with rare instances of contact allergy and type I hypersensitivity reactions. In children with glucose‐6‐phosphate dehydrogenase deficiency, topical application of henna may cause life‐threatening haemolysis. Black henna tattoos will induce contact allergy to its ingredient PPD at an estimated frequency of 2.5%. Once sensitized, the patients may experience allergic contact dermatitis from the use of hair dyes containing PPD. There are often cross‐reactions to other hair dyes, dyes used in textiles, local anaesthetics, and rubber chemicals. The sensitization of children to PPD may have important consequences for health and later career prospects. Systemic toxicity of black henna has been reported in certain African countries.     

Effects of a 3‐hydroxy‐3‐methylglutaryl coenzyme A reductase inhibitor and low‐density lipoprotein on proliferation and migration of keratinocytes

Background Keratinocytes can obtain cholesterol either by de novo synthesis or by extraction, primarily from low‐density lipoprotein (LDL). LDL is internalized following binding to the LDL receptor (LDLR). Because LDLR is expressed at a higher level in the cells of the basal layer of the epidermis, it might be assumed that LDLR upregulation is associated with keratinocyte proliferation. However, the effect of LDLR stimulation on keratinocyte function remains unclear. Objectives To investigate the effects and mechanism of action of pitavastatin and effects of LDL on proliferation and migration of keratinocytes. Methods Pitavastatin, an inhibitor of 3‐hydroxy‐3‐methylglutaryl coenzyme A reductase, was used to induce upregulation of LDLR. LDLR expression was evaluated by immunofluorescence staining, fluorescence‐activated cell sorting, immunohistochemical staining and real‐time polymerase chain reaction (PCR). HaCaT cells and normal human keratinocytes (NHKs) were used for evaluation of migration. 5‐Bromo‐2′‐deoxyuridine incorporation was used to evaluate keratinocyte proliferation and differentiation. C57BL6 mice were used for in vivo evaluation of the effect of topical pitavastatin or lovastatin. Results Pitavastatin was most effective in LDLR induction at a concentration of 1 μmol L^?1 in NHKs. Real‐time PCR showed that pitavastatin significantly increased LDLR and liver X receptor (LXR) β mRNA expression in these cells. Similar results were obtained in vivo. However, pitavastatin had no effect on the migration of NHKs. After the addition of LDL and/or mevalonate concomitantly with pitavastatin to NHK cultures, or topical application of pitavastatin on mouse skin, keratinocyte proliferation was significantly increased. Conclusions Pitavastatin significantly upregulates LDLR in both NHKs and C57BL6 mouse skin, resulting in increased keratinocyte proliferation. LXRβ may be involved in the pitavastatin‐induced keratinocyte proliferation.     

Dapsone hypersensitivity syndrome with circulating 190‐kDa and 230‐kDa autoantibodies

Dapsone has potent anti‐inflammatory effects, and is used in the treatment of leprosy, cutaneous vasculitis, neutrophilic dermatoses, and dermatitis herpetiformis and other blistering disorders. However, it may cause severe adverse reactions such as hypersensitivity syndrome, which is characterized by fever, skin rash, hepatitis and lymphadenopathy. We report a 44‐year‐old female Korean patient with dapsone hypersensitivity syndrome (DHS) that presented as a bullous skin eruption. The patient had a 1‐year history of urticarial vasculitis, treated with antihistamines, prednisolone and dapsone. Although the skin lesions improved, she reported fever, nausea, abdominal pain, jaundice, fatigue and skin rashes. On physical examination, there were generalized erythematous macules and purpura with facial oedema that developed into vesicles on the upper limbs. Histological examination of a skin biopsy of a vesicular lesion found subepidermal oedema with a mixed inflammatory cell infiltrate, including eosinophils in the dermis. Indirect immunofluorescence testing using normal foreskin as substrate revealed IgG deposits in the basement membrane zone. Circulating autoantibodies against antigens of 190 and 230 kDa were found by immunoblotting analysis using epidermal extracts. This case illustrates DHS with the formation of circulating autoantibodies.     

Histamine H1 and H2 receptor antagonists accelerate skin barrier repair and prevent epidermal hyperplasia induced by barrier disruption in a dry environment

Keratinocytes have histamine H1 and H2 receptors, but their functions are poorly understood. To clarify the role of histamine receptors in the epidermis, we examined the effects of histamine receptor antagonists and agonists applied epicutaneously on the recovery of skin barrier function disrupted by tape stripping in hairless mice. Histamine H2 receptor antagonists famotidine and cimetidine accelerated the recovery of skin barrier function, but histamine and histamine H2 receptor agonist dimaprit delayed the barrier repair. Application of compound 48/80, a histamine releaser, also delayed the recovery. Imidazole, an analog of histamine, had no effect. The histamine H1 receptor antagonists diphenhydramine and tripelennamine accelerated the recovery. Histamine H3 receptor agonist Nalpha-methylhistamine and antagonist thioperamide had no effect. In addition, topical application of famotidine or diphenhydramine prevented epidermal hyperplasia in mice with skin barrier disrupted by acetone treatment in a dry environment (humidity < 10%) for 4 d. In conclusion, both the histamine H1 and H2 receptors in the epidermis are involved in skin barrier function and the cutaneous condition of epidermal hyperplasia.     

Induction of eosinophil‐ and Th2‐attracting epidermal chemokines and cutaneous late‐phase reaction in tape‐stripped skin

Abstract: Skin barrier damage induces various harmful or even protective reactions in the skin, as represented by enhancement of keratinocyte cytokine production. To investigate whether acute removal of stratum corneum modulates the production of chemokines by epidermal cells, we treated ears of BALB/c and C57BL/6 mice by tape‐stripping, or acetone‐rubbing as a control of acute barrier disruption procedure. There was no difference between the tape‐stripped and acetone‐rubbed skin sites in the increased and recovered levels of transepidermal water loss. The mRNA expression levels of all the chemokines tested, including Th1 chemokines (CXCL10, CXCL9 and CXCL11), Th2 chemokines (CCL17 and CCL22) and eosinophil chemoattractant (CCL5), were higher in the epidermal cells from BALB/c than in those of C57BL/6 mice. In particular, CCL17, CCL22 and CCL5 were remarkably elevated in BALB/c mice and augmented by tape‐stripping more markedly than acetone‐rubbing, whereas Th1 chemokines were enhanced by acetone‐rubbing more remarkably. Tape‐stripping induced dermal infiltration of eosinophils in BALB/c but not C57BL/6 mice. In a contact hypersensitivity model, where BALB/c mice were sensitized on the abdomen and challenged on the ears with fluorescein isothiocyanate, mice exhibited higher ear swelling responses at the late‐phase as well as delayed‐type reactions, when challenged via the tape‐stripped skin. The challenge via tape‐stripped skin augmented the expression of IL‐4 and CCR4 in the skin homogenated samples, indicating infiltration of Th2 cells. These findings suggest that acute barrier removal induces the expression of Th2 and eosinophil chemokines by epidermal cells and easily evokes the late phase reaction upon challenge with antigen.     

Characterization of surfactant-induced skin damage through barrier recovery induced by pseudoacylceramides

BACKGROUND AND OBJECTIVE: To determine how much barrier-reinforcing effects of ceramides contribute to prevent the surfactant-induced cutaneous deterioration. METHODS: We compared the effects of topical application of two types of pseudoceramides on cutaneous deterioration induced by sodium dodecyl sulfate (SDS) treatment for 10 days in association with alterations of barrier function. RESULTS: Daily application of pseudoacylceramide immediately after each SDS treatment significantly prevented the marked elevation of transepidermal water loss, which was accompanied by a marked abrogation of the increased expression in intercellular adhesion molecule 1 by epidermal cells as well as by suppressed epidermal hyperplasia. In contrast, topical application of a nonacylated pseudoceramide with poor barrier-reinforcing potential showed less preventive effects on cutaneous deterioration. CONCLUSION: These results strongly suggest that perturbation of the skin barrier is a causative factor in surfactant-induced cutaneous changes and that reinforcing the barrier function by ceramide application is effective in preventing the surfactant-induced skin deterioration.     

Topical hesperidin prevents glucocorticoid‐induced abnormalities in epidermal barrier function in murine skin

Systemic and topical glucocorticoids (GC) can cause significant adverse effects not only on the dermis, but also on epidermal structure and function. In epidermis, a striking GC‐induced alteration in permeability barrier function occurs that can be attributed to an inhibition of epidermal mitogenesis, differentiation and lipid production. As prior studies in normal hairless mice demonstrated that topical applications of a flavonoid ingredient found in citrus, hesperidin, improve epidermal barrier function by stimulating epidermal proliferation and differentiation, we assessed here whether its topical applications could prevent GC‐induced changes in epidermal function in murine skin and the basis for such effects. When hairless mice were co‐treated topically with GC and 2% hesperidin twice‐daily for 9 days, hesperidin co‐applications prevented the expected GC‐induced impairments of epidermal permeability barrier homoeostasis and stratum corneum (SC) acidification. These preventive effects could be attributed to a significant increase in filaggrin expression, enhanced epidermal β‐glucocerebrosidase activity and accelerated lamellar bilayer maturation, the last two likely attributable to a hesperidin‐induced reduction in stratum corneum pH. Furthermore, co‐applications of hesperidin with GC largely prevented the expected GC‐induced inhibition of epidermal proliferation. Finally, topical hesperidin increased epidermal glutathione reductase mRNA expression, which could counteract multiple functional negative effects of GC on epidermis. Together, these results show that topical hesperidin prevents GC‐induced epidermal side effects by divergent mechanisms.     

Topical calcitriol protects from UV‐induced genetic damage but suppresses cutaneous immunity in humans

Please cite this paper as: Topical calcitriol protects from UV‐induced genetic damage but suppresses cutaneous immunity in humans. Experimental Dermatology 2010; 19 : e23‐e30. Abstract: Calcitriol, the biologically active form of vitamin D, has been reported to cause both suppressive and protective immune effects in mice. Its immune effects in vivo in humans are unclear. We investigated the in vivo effects of topical calcitriol on minimal erythema dose and skin immune responses in healthy volunteers. We found that calcitriol did not protect from ultraviolet (UV)‐induced erythema (sunburn) when applied either 24 h before or immediately after irradiation, although it decreased the density of sunburn cells and thymine dimers seen on biopsy when applied 24 h before and again immediately after irradiation. Using the Mantoux reaction as a model of skin immunity, we found that topical calcitriol applied at high total doses reduced the Mantoux responses of nearby untreated, unirradiated skin, suggesting a para‐local or systemic immunosuppressive effect not observed with lower calcitriol doses. We then measured UV‐induced suppression of Mantoux reactions at vehicle‐treated sites and sites treated with low‐dose calcitriol, and found that calcitriol neither reduced nor enhanced UV‐induced immunosuppression. Despite calcitriol reducing UV‐induced DNA damage, which should protect the immune system, it has immunosuppressive effects in our model which may help to explain the efficacy of analogues such as calcipotriol in the treatment of psoriasis.     

Olopatadine hydrochloride accelerates the recovery of skin barrier function in mice

BACKGROUND: The skin barrier function in patients with atopic dermatitis is disrupted and prolonged topical steroid therapy produces epidermal barrier disturbance. Olopatadine hydrochloride (olopatadine; Allelock; Kyowa Hakko Kogyo Co., Ltd, Shizuoka, Japan) is an antiallergic drug with histamine H(1) receptor antagonistic action. This drug alleviates skin inflammation and decreases the number of scratching episodes in a murine model of chronic contact dermatitis. OBJECTIVES: To investigate the effects of olopatadine and a steroid on the recovery of skin barrier function after barrier disruption in mice. METHODS: The skin barrier of the ears of mice was disrupted by tape stripping. The recovery of skin barrier function was monitored by measurement of transepidermal water loss (TEWL) after barrier disruption. Epidermal hyperplasia was induced by repeated tape stripping for 7 days. Olopatadine was administered orally once daily from 3 days before the first barrier disruption. Betamethasone 17-valerate (betamethasone) was applied topically once daily from 3 days before barrier disruption. RESULTS: Tape stripping led to a significant increase in TEWL. TEWL decreased with time after tape stripping and the skin barrier function recovered by over 60% within 9 h after tape stripping. The recovery of skin barrier in olopatadine-treated mice was significantly accelerated, compared with that in vehicle-treated mice. In contrast, the skin barrier recovery in mice treated with topical betamethasone was significantly delayed, compared with that in vehicle-treated mice. Combined treatment with olopatadine and betamethasone ameliorated the delay in barrier recovery induced by topical treatment with betamethasone. In addition, olopatadine significantly prevented the increase in epidermal thickness induced by prolonged barrier disruption. CONCLUSIONS: These results suggest that systemic administration of olopatadine accelerates the recovery of skin barrier function and ameliorates the adverse effects of topical steroids on skin barrier recovery.     

Topical administration of the pan‐Src kinase inhibitors,dasatinib and LCB 03‐0110, prevents allergic contact dermatitis in mice

Background Allergic contact dermatitis (ACD) is a delayed type of T cell‐mediated cutaneous inflammatory response, in which multiple cell types are involved. Dasatinib and LCB 03‐0110 are small molecule multityrosine kinase inhibitors, and they share remarkably similar target kinases such as the c‐Src family, Btk and Syk, which play key roles in the cell signalling of T cells and other inflammatory cells. Objectives To test the anti‐ACD activity of dasatinib and LCB 03‐0110 and compare it with that of tacrolimus (FK506) and triamcinolone acetonide (a glucocorticoid), which are widely used for topical treatment of ACD, and to examine the two compounds for their capacity to induce skin atrophy, a side‐effect. Methods ACD was induced on the ears of mice by repeated topical application of oxazolone. Each test compound was then topically applied on the ear. Ear swelling, epidermal thickness and levels of inflammatory cytokines were measured. The skin atrophy induced by the compounds was tested during prolonged application on the dorsal skin of hairless mice, followed by haematoxylin and eosin staining. Results Dasatinib and LCB 03‐0110 suppressed the symptoms of ACD such as ear swelling, increase in epidermal thickness and synthesis of inflammatory cytokines (i.e. interleukin‐1β, tumour necrosis factor‐α and interferon‐γ) in a dose‐dependent manner. The two compounds showed near‐equal potency to tacrolimus; however, their potency was lower than that of triamcinolone acetonide. Prolonged treatment with the two compounds did not induce any skin atrophy, whereas use of steroidal agents induced severe atrophy. Conclusions Dasatinib and LCB 03‐0110 could be used as effective agents for the treatment of ACD without the adverse side‐effect of skin atrophy.     

The 24‐hr, 28‐day,and 7‐day post‐moisturizing efficacy of ceramides 1, 3, 6‐II containing moisturizing cream compared with hydrophilic cream on skin dryness and barrier disruption in senile xerosis treatment

Direct replacement of decreased ceramides in the stratum corneum can be efficacious for skin hydration, skin barrier function, and skin pH. Our study aimed to evaluate the 24‐hr, 28‐day, and 7‐day post‐moisturizing efficacy of ceramide‐containing moisturizer in senile xerosis treatment. A split site, double‐blinded, randomized, controlled study was conducted in 24 senile subjects (91.7% females, mean age 54.83 ± 5.45 years) with mild to moderate xerosis, who were randomized to receive ceramide‐containing moisturizer or hydrophilic cream, daily applied on each side of the shin. A single application of ceramide‐containing moisturizer increased skin hydration, while improving transepidermal water loss (TEWL) and skin pH for up to 24 hr, with statistically significant difference. After 28 days of twice‐daily application, more significant improvement on skin hydration, barrier function, and skin pH was observed in those with ceramide‐containing moisturizer at all‐time points. At day 28, there was a statistically significant decrease of hemoglobin index, wrinkle, and texture on the ceramide treated side. The 7‐day post‐moisturizing efficacy on the ceramide treated side was superior for skin hydration, TEWL, skin pH, and wrinkle. Thus, the ceramide‐containing moisturizer can be a novel promising treatment for senile xerosis.     

Topical application of TRPM8 agonists accelerates skin permeability barrier recovery and reduces epidermal proliferation induced by barrier insult: role of cold‐sensitive TRP receptors in epidermal permeability barrier homoeostasis

Please cite this paper as: Topical application of TRPM8 agonists accelerates skin permeability barrier recovery and reduces epidermal proliferation induced by barrier insult: role of cold‐sensitive TRP receptors in epidermal permeability barrier homoeostasis. Experimental Dermatology 2010; 19 : 791–795. Abstract: TRPA1 and TRPM8 receptors are activated at low temperature (A1: below 17°C and M8: below 22°C). Recently, we observed that low temperature (below 22°C) induced elevation of intracellular calcium in keratinocytes. Moreover, we demonstrated that topical application of TRPA1 agonists accelerated the recovery of epidermal permeability barrier function after disruption. In this study, we examined the effect of topical application of TRPM8 modulators on epidermal permeability barrier homoeostasis. Immunohistochemical study and RT‐PCR confirmed the expression of TRPM8 or TRPM8‐like protein in epidermal keratinocytes. Topical application of TRPM8 agonists, menthol and WS 12 accelerated barrier recovery after tape stripping. The effect of WS12 was blocked by a non‐selective TRP antagonist, Ruthenium Red, and a TRPM8‐specific antagonist, BTCT. Topical application of WS12 also reduced epidermal proliferation associated with barrier disruption under low humidity, and this effect was blocked by BTCT. Our results indicate that TRPM8 or a closely related protein in epidermal keratinocytes plays a role in epidermal permeability barrier homoeostasis and epidermal proliferation after barrier insult.     

Characterization of skin lesions induced by skin‐tropic α‐ and β‐papillomaviruses in a patient with epidermodysplasia verruciformis

Epidermodysplasia verruciformis (EV) is a rare, lifelong, autosomal recessive skin disease associated with an unusual susceptibility to infections with ubiquitous β‐human papillomaviruses (β‐HPVs), and in some cases also skin‐tropic α genotypes. In this case report, HPV infection patterns were correlated with pathology and clinical manifestations of skin lesions from a patient with EV, without loss‐of‐function mutations in the EVER genes. HPV infection was investigated by both polymerase chain reaction (PCR) and laser capture microdissection (LCM) PCR, alongside immunofluorescence for the viral proteins E4 and L1. Analysis of eyebrow hair bulbs revealed multiple β‐genus HPV infections, including HPV20 and HPV24, which were consistently found in all 11 skin lesions on the patient. Six lesions were also positive for the skin tropic α‐genotype, HPV27. Clear‐cut differences between two wart‐like lesions, one caused by a skin‐tropic α‐genotype and the other by β‐genotypes (as detected by LCM PCR) are shown, including the high cellular proliferation rate in β‐HPV‐induced lesions. Widespread expression of the early protein E4 was also evident in skin lesions positive for HPV20 by LCM PCR in both tumours and nearby intraepidermal proliferative areas. L1 expression was restricted to areas of intraepidermal proliferation showing productive infection. The patient's inability to control HPV infections is conclusive to the uncontrolled replication of few genotypes from both α and β genera, which cause proliferative lesions with clear‐cut clinical and histological features.