Efficacy and safety of 1064-nm fractional picosecond laser for the treatment of postmastectomy scars in transgender men: A randomized controlled trial.

OBJECTIVES: Subcutaneous mastectomy is a crucial component of gender affirmation therapy for transgender men (TM), but the scars that result from this procedure can frequently impair their quality of life. This study aimed to assess the efficacy and safety of 1064-nm fractional picosecond laser (FxPico) treatment for hypertrophic and atrophic postmastectomy scars in TM. METHODS: Twenty-two patients with a total of 35 pairs of bilateral symmetric mastectomy scars were enrolled. One of each pair of symmetric scars was randomly assigned to receive four FxPico treatments at 4-week intervals. All scars were evaluated using the modified Vancouver Scar Scale (mVSS) and three-dimensional imaging for scar roughness, melanin index, and hemoglobin index before each treatment session and at 1, 3, and 6 months following the last treatment. Additionally, participant-rated scar satisfaction (PSS) and scar improvement (Global Assessment Score, GAS), as well as adverse events were recorded. RESULTS: During the 6-month follow-up period after the end of laser treatment sessions, the treated scars showed significant reductions in the mVSS compared to the untreated controls (p < 0.001), whereas the melanin index and hemoglobin index were not significantly different. Subgroup analysis of hypertrophic scars demonstrated statistically significant reductions in mVSS at 1 (p = 0.003) and 3 months (p = 0.041) after the end of laser treatments. PSS was significantly higher on the laser-treated scars than the controls (p = 0.008), and a participant-rated GAS of 2.95 ± 0.65 was found. There were no serious adverse events reported. CONCLUSIONS: 1064-nm FxPico could be utilized to treat mastectomy scars among TM, particularly the hypertrophic type.

Lichen Sclerosus of the Labial Mucosa: A Case Report and Literature Review.

Lichen sclerosus (LS) is an uncommon, chronic, inflammatory mucocutaneous disorder found predominantly in females with unknown etiology. It presents as a white sclerotic plaque commonly located on the anogenital area. Extragenital LS is less prevalent, and LS affecting the oral mucosa is extremely rare, with only 39 biopsy-confirmed cases reported in the literature. Due to its several mimicking conditions, histological examination is usually required for a definitive diagnosis, particularly in patients with oral LS. Current evidence-based treatment recommendations for oral LS are unavailable; however, most cases tend to improve after treatment with topical or intralesional corticosteroids. We report a case of a 58-year-old female referred from the otolaryngology department for evaluating an asymptomatic whitish sclerotic plaque on the lower lip mucosa that had existed for 1 year. Following a punch biopsy, the patient was diagnosed with LS of labial mucosa. The condition improved after 2 months of treatment with topical and intralesional corticosteroids. The present case report raises awareness in recognizing oral LS and contributes to knowledge of this rare disorder.

Two Case Reports of Elastolytic Giant Cell Granuloma on the Palms.

Elastolytic giant cell granuloma (EGCG) is a rare granulomatous reaction hypothesized to occur because of the altered antigenicity of elastic fibers, resulting in cellular immunological reactions. The hallmarks of EGCG include elastolysis, elastophagocytosis, and multinucleated giant cell infiltrations. EGCG was first described as an actinic granuloma or annular elastolytic giant cell granuloma that classically presents as centrifugally expanding annular plaques on sun-exposed areas. It was recently named EGCG due to reports of non-annular lesions in various sun-protected areas. Hand involvement has been described but is almost exclusively confined to the dorsal and lateral aspects of the hands. Herein, we report two cases of EGCG on the palms, an unusual site of presentation, that were successfully treated with topical, high-potency corticosteroids. EGCG should be included in the differential diagnosis in cases of annular skin lesions located on the marginal area of the palms.

Cutaneous Methotrexate-Related Epstein-Barr Virus-Positive Diffuse Large B-Cell Lymphoma in a Patient with Granulomatous Cutaneous T-Cell Lymphoma: A Case Report and Literature Review.

Methotrexate-related lymphoproliferative disorders (MTX-LPDs) are immunodeficiency diseases following methotrexate (MTX) administration, mainly occurring in rheumatoid arthritis patients. Although uncommon, MTX-LPDs have been reported in some patients with psoriasis, dermatomyositis, and cutaneous T-cell lymphoma (CTCL) who received MTX. Granulomatous mycosis fungoides (GMF) is a rare subtype of cutaneous T-cell lymphoma, where MTX is one of the treatment options in recalcitrant cases. Herein, we report a case of a 72-year-old female patient with GMF who additionally developed cutaneous Epstein-Barr virus (EBV)-positive diffuse large B-cell lymphoma (DLBCL) during MTX treatment. According to the 5th edition of the WHO classification of Haematolymphoid Tumors (WHO-HAEM), this condition is currently categorized as "lymphoma arising in immunodeficiency/dysregulation". In this article, we also reviewed published literature on cutaneous MTX-LPDs in the setting of CTCL. This entity should be considered in cases of new, atypical skin nodules and/or plaques in CTCL patients receiving long-term MTX treatment.

Granular Parakeratosis of the Eccrine Ostium: A Case Report.

Granular parakeratosis (GP) is a unique keratotic disorder that often affects the intertriginous areas. GP usually presents as erythematous or brownish hyperkeratotic papules or plaques and can be further classified into five types. GP of the eccrine ostium is a rare subtype; its pathological defects are mainly localized to the stratum corneum of the eccrine ostia. Due to its rarity, there is usually a delay in diagnosing GP, and these patients are often misdiagnosed with other dermatological conditions. In this report, we present the case of a 64-year-old Thai female who presented with recurrent pruritic erythematous rashes on her neck since approximately 40 years. She was previously diagnosed with eczema or folliculitis. Histopathological examination confirmed a final diagnosis of GP of the eccrine ostium. She was advised to avoid excessive heat and keep her intertriginous areas dry. Her condition improved significantly during the follow-up visit.

Scleroderma-Like Lupus Panniculitis: A Case Report and Literature Review.

Sclerodermic or scleroderma-like lupus erythematosus panniculitis (SLEP) shares both clinical and histopathological features between lupus panniculitis and localized scleroderma. It is exceedingly rare. We herein report a case of SLEP manifested with a solitary, firm-to-hard, erythematous plaque in an Asian woman. This patient responded well to intralesional corticosteroid and antimalarials. We have reviewed the pathogenesis of fibrosis in patients with chronic cutaneous lupus erythematosus as well as documented cases of SLEP in the literature.

Characterizing Dermatological Conditions in the Transgender Population: A Cross-Sectional Study.

Purpose: This study aimed to demonstrate the effects of gender-affirming hormone therapy (GAHT) and gender-affirming procedures on the skin in transgender individuals. Methods: We conducted a cross-sectional study among transgender people. Skin conditions related to GAHT were assessed, including acne (using the Investigator's Global Assessment, IGA), postacne sequelae, melasma, hypertrichosis in androgen-sensitive areas (HAAs) in transgender men (TM) and hirsutism in transgender women (TW) (using the modified Ferriman-Gallwey score, mFG score), and hair loss (using the Hamilton-Norwood and Ludwig scale) at baseline, 6 months after GAHT, and the day on which the questionnaire was completed. Dermatological problems after gender-affirming procedures were evaluated. Results: A total of 159 patients, including 134 TM and 25 TW, were eligible to participate. The median duration of GAHT was 23 and 36 months in TM and TW, respectively. In TM, the median IGA score of facial acne increased from 1 at baseline to 3 after 6 months and decreased to 2 after 2 years of GAHT. The mFG score indicated HAA in all TMs after testosterone treatment. A total of 88.1% of TM had no hair loss before hormone therapy. However, after 2 years of GAHT, 76.1% of TM developed male pattern hair loss (MPHL), and 26.1% of them had moderate-to-severe MPHL. In TW, the median IGA and mFG scores decreased after 3 years of hormone therapy, and the proportion of female pattern hair loss (FPHL) in TW increased to 16% after GAHT. In both groups, the most common skin complication after gender-affirming surgery was hypertrophic scarring. Conclusions: GAHT in TM resulted in acne and MPHL, whereas GAHT in TW caused melasma and FPHL.

Dermoscopic Features and Their Diagnostic Values Among Common Inflammatory and Infectious Dermatoses: A Cross-Sectional Study.

Background: Dermoscopy is a non-invasive tool widely used to improve the diagnostic accuracy of general dermatological conditions. Objective: To determine the dermoscopic features and their diagnostic value in distinguishing common inflammatory and infectious dermatoses. Materials and Methods: A cross-sectional study was conducted on patients clinically diagnosed with common inflammatory or infectious skin diseases. Baseline characteristics and clinical and dermoscopic findings were recorded. Dermoscopic variables were analyzed using a correlation matrix. A skin biopsy was performed for each patient for a definitive diagnosis. Results: Of 102 patients, 43 with dermatitis, 30 with psoriasis, 14 with lichen planus (LP), 5 with pityriasis rosea (PR), and 10 with others were included. Dull red background, patchy vessels, and scales showed significant positive correlations with dermatitis (r = 0.401, 0.488, and 0.327, respectively; p < 0.01), whereas bright red background, glomerular vessels, regular vascular distribution, and diffuse scales revealed significant positive correlations with psoriasis (r = 0.412, 0.266, 0.798, and 0.401, respectively; p < 0.01). For LP, whitish reticulate structures, purplish background, and dotted vessels mixed with linear vessels in the peripheral distribution were significantly positively correlated (r = 0.831, 0.771, 0.224, and 0.558, respectively; p < 0.05). Yellowish background and peripheral scales were predictive of PR diagnosis (r = 0.254 and 0.583, respectively; p < 0.01). Conclusion: Dermoscopy can be used as an adjunctive tool to differentiate conditions among common inflammatory and infectious dermatoses in order to minimize unnecessary invasive diagnostic procedures.

A comparative study of pain perception during the microfocused ultrasound procedure between topical anesthesia and combined topical anesthesia with forced air cooling.

BACKGROUND: The experience of pain during microfocused ultrasound with visualization (MFU-V) treatment is common and crucial for dictating patient satisfaction and retention. OBJECTIVE: To compare the pain perception during the MFU-V procedure between two pain reduction methods (topical anesthesia alone versus combined topical anesthesia with forced air cooling). MATERIALS AND METHODS: This was a prospective, single-blinded, randomized controlled trial. A square area on the inner side of both arms of healthy volunteers was marked as an experimental site and randomly assigned to receive each pain reduction method: topical anesthesia or combined topical anesthesia with forced air cooling. Thereafter, MFU-V was performed with a 4.5 MHz, 4.5 mm transducer (10 lines, 0.9 J) followed by a 7 MHz, 3.0 mm transducer (10 lines, 0.3 J). The visual analog scale (VAS) for pain was measured immediately after 4.5 mm transducer (T1a), immediately after 3.0 mm transducer (T1b), and after the entire procedure (T2). RESULTS: Twenty-one participants with a mean (SD) age of 34.67 (±6.18) years were enrolled. The mean (±SD) pain score of combined topical anesthesia with forced air cooling-treated area was 5.40 (±1.64), 4.80 (±1.63), and 5.40 (±1.56) at T1a, T1b, and T2, respectively. The mean pain score for topical anesthesia-treated areas was 5.89 (±1.45), 5.00 (±1.72), and 5.76 (±1.67) at T1a, T1b, and T2, respectively. There were no statistically significant differences in the pain perception between the two methods. CONCLUSION: The addition of forced air cooling is not beneficial for pain reduction during the MFU-V procedure because its temperature reduction effect cannot be delivered to the deep parts of the skin, which is the target site of MFU-V.

The effect of combined of hyaluronic acid dermal filler and microfocused ultrasound treatment: A clinicopathological study.

OBJECTIVES: Microfocused ultrasound (MFU) and hyaluronic acid (HA) filler injection are increasingly popular aesthetic procedures. HA filler injection is generally recommended after MFU if combined treatment is required in a single visit. However, data regarding the safe and optimal time of MFU treatment after HA injection is still limited. The purpose of this study was to evaluate the degree of HA loss when performing MFU treatment after dermal filler injection. METHODS: Fourteen subjects were recruited in this pilot study. HA was injected intradermally on four 2 × 2 cm areas at the abdomen (0.25 ml/site). Site A was served as control whereas site B, C, D were treated with MFU using 1.5 mm transducer at 60 min, Day 14, and Day 28 after the injection, respectively. All experimental sites were biopsied using a 3-mm punch biopsy to evaluate the histopathological profile at baseline and Day 56. Grading of the quantity of retained HA was evaluated by a blinded experienced dermatopathologist. RESULTS: All 14 subjects completed the study. One subject has been excluded due to the poor quality of histopathologic slides. Seven subjects (53.9%) at site B and 6 subjects (46.2%) at site C had HA loss at Day 56 compared with baseline. The mean HA grading at baseline and Day 56 was 3.7 vs. 2.8 (p < 0.001) at site B and 3.7 vs. 3.0 (p = 0.001) at site C, respectively. There was no statistical difference between the mean HA grading at baseline and Day 56 at site D (3.7 vs. 3.3, p = 0.073). No inflammation or granuloma was observed on Day 56 of the study. CONCLUSIONS: MFU treatment after HA injection appears to be safe. However, some degree of HA loss was observed if MFU treatment was done within 2 weeks after HA injection.

The effect of combined hyaluronic acid filler injection and radiofrequency treatment: A clinic histological analysis.

BACKGROUND: Hyaluronic acid (HA) filler injections have increased in popularity. They are usually performed in combination with other treatment modalities, including lasers and energy-based devices, to enhance cosmetic results. Theoretically, HA and other filler injections should be performed after laser- or energy-based device treatments. In some instances, however, practitioners are asked to administer laser- or energy-based device treatment after HA dermal filler injection. There is a concerning possibility of HA filler degradation as a result of bulk heating generated by lasers or energy-based devices, especially radiofrequency (RF). AIM: To evaluate the effect of RF treatment at different time points on HA degradation in vivo, using clinicohistological analysis. PATIENTS/METHODS: Fourteen volunteers were recruited and received intradermal HA filler injections in four sites on the abdomen. One site served as the control, and the other three sites were treated with monopolar RF on the same day after injection, at 14 and 28 days post-injection. Skin biopsies were performed at baseline and 56 days after HA injection. Histopathological sections were reviewed for residual filler in the tissue. RESULTS: The results showed that HA grading scores decreased in five (35.71%), one (7.14%), and one (7.14%) participants when RF was performed immediately, 14 and 28 days after injection, respectively. CONCLUSION: In conclusion, RF treatment after HA filler injection may affect the integrity of the HA filler in the tissue, especially if RF treatment was performed on the same day after HA injection.

Intralesional Measles, Mumps, Rubella Vaccine versus Tuberculin Purified Protein Derivative Injections in the Treatment of Palmoplantar and Periungual Warts: A Double-Blind Randomized Controlled Trial.

BACKGROUND: Palmoplantar and periungual warts tend to be recalcitrant. Intralesional immunotherapy can provide high efficacy with additional benefit to distant warts. However, evidence on comparative effects between intralesional immunotherapy with measles, mumps, rubella vaccine (MMR) and tuberculin purified protein derivative (PPD) and roles of dermoscopy in predicting treatment outcomes in palmoplantar/periungual warts is limited. OBJECTIVES: The study aimed to compare efficacy and safety of intralesional MMR and PPD injections in treatment of palmoplantar/periungual warts and explore associations between dermoscopic findings and treatment outcomes. METHODS: We conducted a double-blind randomized controlled trial involving 40 patients with palmoplantar/periungual warts who were equally assigned to receive MMR or PPD. Intralesional injection was done every 2 weeks until clearance or maximum of 5 treatments. RESULTS: Complete resolution was higher in MMR than PPD group (90.0% vs. 80.0% in index lesion and 81.3% vs. 54.6% in distant lesions, respectively), although the differences were statistically nonsignificant. Dermoscopic findings were not significantly associated with complete resolution. Local swelling, i.e., the most common adverse event, occurred more frequently in PPD (40.0%) than MMR group (10.0%). CONCLUSION: This study suggests that intralesional immunotherapy with either MMR or PPD is efficacious in palmoplantar/periungual warts, with MMR showing a trend toward higher clearance and lower adverse events.

Coexistence of Discoid Lupus Erythematosus and Paraneoplastic Pemphigus: A Case Report and Literature Review.

Pemphigus and lupus erythematosus are both B-cell-mediated autoimmune diseases, dependent on autoreactive CD4+ T lymphocytes to modulate autoimmune B-cell response. Many forms of pemphigus have been reported to occur in association with systemic lupus erythematosus (SLE) as well as other autoimmune diseases. However, it remains unclear whether this association occurs because of a shared immunopathogenesis or the coexistence may be coincidental. We hereby present a case report of discoid lupus erythematosus and paraneoplastic pemphigus associated with marginal zone lymphoma in a 54-year-old Thai man who had persistent oral erosions for 1 year together with generalized polymorphic cutaneous eruptions for 2 months. Simultaneous occurrence of paraneoplastic pemphigus and discoid lupus erythematosus without SLE has never been reported in the same individual. Hydroxychloroquine, immunosuppressive agents including prednisolone and azathioprine together with chemotherapy were given to treat these conditions.

Pityriasis Lichenoides Et Varioliformis Acuta and Lymphomatoid Papulosis Type F: A Case Report of Two Entities in One Patient.

Pityriasis lichenoides et varioliformis acuta (PLEVA) and lymphomatoid papulosis (LyP) are uncommon inflammatory skin disorders that occasionally share clinicopathological features. Differentiating between the two entities remains problematic, and a definitive diagnosis usually requires multi-step investigations, which is an enormous challenge to physicians. We hereby report a rare case of a 22-year-old female patient diagnosed with PLEVA who later developed LyP type F, a new histological variant of LyP. Our report highlights that long-term follow-up is essential to determine associated hematologic malignancies, particularly in cases with recalcitrant or progressive cutaneous lesions of PLEVA and/or LyP.

Variation of Hair Follicle Counts among Different Scalp Areas: A Quantitative Histopathological Study.

INTRODUCTION: Scalp biopsy is a standard method for the definitive diagnosis of alopecia. The hair count parameters of each scalp area remain unclear. This study aimed to determine hair count values at different scalp locations from histopathology and to establish reference values for each part of the scalp. METHODS: We obtained biopsy specimens from the frontal, vertex, temporoparietal, and occipital areas of the scalps of normal deceased subjects. All specimens were evaluated for the number of follicular units, hair counts, hair types, and stages of the hair cycle. RESULTS: In total, 240 specimens were collected from 60 cadavers. Across all scalp sites, the temporoparietal area showed the lowest mean hair count, number of follicular units, terminal and vellus hairs, and terminal-to-vellus hair ratio. The average anagen-to-telogen hair ratio was comparable across all scalp sites. This study did not observe a significant association of hair parameters with gender differences or increasing age in all scalp areas. CONCLUSIONS: The present study revealed the diversity of the hair index among different scalp areas and suggested that normal hair count values should be separately standardized on each scalp region. Our findings may provide useful reference values for the histopathological evaluation of hair disorders in Asians.

A comprehensive review of treatment options for recalcitrant nongenital cutaneous warts.

INTRODUCTION: The treatment of recalcitrant nongenital cutaneous warts has always been challenging for dermatologists as they often recur and relapse. Multiple treatment options have been investigated to improve the outcome. This review provides an overview of the current treatment modalities and summarizes the efficacy and side effects of each treatment option for recalcitrant nongenital cutaneous warts. METHODS: A PubMed search was performed through July 2019 to include all English language reports investigating the treatment for recalcitrant nongenital cutaneous warts, regardless of design. RESULTS: A total of 144 studies were included in this review. The treatment options for recalcitrant nongenital cutaneous warts can be divided into three groups: destructive treatment, immunotherapy, and cytotoxic agents. Although both destructive therapies and cytotoxic agents demonstrated high complete response rates, immunotherapy, which is a minimally invasive method, was superior in terms of the clearance of distant warts. Intralesional mumps-measles-rubella injections and purified protein derivatives currently demonstrate high efficacy with well-established clinical evidence. CONCLUSIONS: Many upcoming treatment modalities, especially immunotherapy, are promising. However, more comparative studies are required to verify the efficacy and safety profile.

Comparative Analyses of Clinical Features, Histopathology, and CD123 Immunohistochemistry of Oral Lupus Erythematosus, Lichen Planus, and Other Lichenoid Lesions.

BACKGROUND: Oral lupus erythematosus (OLE) and oral lichen planus (OLP) are among the common causes of oral lichenoid lesions (OLLs). The differential diagnosis among causes of OLLs, particularly between OLE and OLP, is challenging as they have significant clinical and histopathological overlap. OBJECTIVES: To compare and summarize the clinical, histopathological, and direct immunofluorescence (DIF) findings between OLE, OLP, and other OLLs and to explore the diagnostic value of CD123 immunohistochemistry. METHODS: A retrospective study on patients with OLE, OLP, and other OLLs was performed between January 2014 and December 2019. The baseline characteristics, the clinical, histopathological, and DIF features, as well as CD123 immunohistochemistry for plasmacytoid dendritic cells (PDCs) were statistically analyzed and compared between groups. RESULTS: Of 70 patients, 12 had OLE, 39 had OLP, and 19 had other OLLs. Oral erosions/ulcers were the most common findings in all three groups. Red macules, telangiectases, and discoid plaques were more common in OLE patients, while OLP cases were typified by reticulated patches (p < 0.05). Additionally, white patches were found more often in other OLLs than in both OLE and OLP (p = 0.002). Histologically, mucosal atrophy, basal vacuolization, and perivascular infiltrate were observed in OLE, whereas OLP specimens possessed mucosal hyperplasia, hypergranulosis, and compact orthokeratosis (p < 0.05). Mucosal spongiosis was a histologic feature that favored other OLLs over OLE and OLP (p < 0.001). Data on DIF were nonspecific for all three conditions. For immunohistochemical staining, the median number of total CD123+ PDCs was observed to be higher in OLE than OLP in the mucosal-submucosal junction (MSJ) (p = 0.021), the superficial perivascular area (p = 0.026), and the superficial and deep perivascular areas (p = 0.001). Likewise, PDCs in clusters ≥2+ were seen in significantly higher numbers on OLE than OLP along the MSJ (p = 0.002), the superficial perivascular area (p < 0.001), as well as the superficial and deep perivascular areas (p = 0.011). CD123+ PDCs were found to be significantly more numerous in both OLE and OLP than other OLLs in all of the abovementioned areas (all p < 0.05). CONCLUSION: While there are some differences in the clinicopathological features between OLE, OLP, as well as other OLLs, a significant overlap remains. The quantity and distribution pattern of CD123 immunohistochemical staining has a diagnostic implication in differentiating OLE from OLP and other OLLs.

Histopathological Evidence of Occipital Involvement in Male Androgenetic Alopecia.

Background: The occipital region of the scalp is generally accepted as an unaffected area of androgenetic alopecia (AGA) for both genders. However, evidence of AGA involving the occipital scalp has been demonstrated in women; meanwhile, it is unclear whether occipital involvement also occurs in men. Objective: We aimed to determine if there is occipital involvement in men with AGA. Methods: This case-control study compared hair counts of scalp biopsy specimens from the occipital region of 82 men with Hamilton-Norwood III-VII and 82 unaffected men. Results: The mean ages of men with AGA and controls were 40.1 ± 8.9 and 38.6 ± 10.5 years, respectively (P = 0.291). A significant decrease in total hair follicles, terminal hair follicles, follicular units and terminal to vellus (T:V) ratio, along with a significant increase in follicular stelae was indicated in the AGA group compared to controls (all P < 0.05). Subgroup analyses revealed that average counts of total hair follicles, terminal hair follicles and T:V ratios were also significantly lower in males with Hamilton-Norwood VI and VII than in controls (all P < 0.05). There were no correlations between increasing age and hair count parameters, but a significant negative association was found between total follicle numbers and disease duration (r = -0.23, P = 0.02). Conclusions: AGA can involve the occipital area of male patients with advanced disease. Therefore, the occiput of particular cases should not be used to determine reference data for normal scalp hair, and preoperative measurements of miniaturized hairs in the donor site are strongly recommended in all persons undergoing hair transplantation.

Clinicopathological Characteristics Related to Etiologies of Erythema Nodosum: A 10-Year Retrospective Study.

BACKGROUND: Erythema nodosum (EN) is the most common panniculitis associated with a wide variety of conditions. Updated studies regarding the clinicopathological manifestations related to etiologies of EN and its prognosis are limited. OBJECTIVE: We aimed to explore the clinicopathological features in relation to the etiologies of EN and determine characteristics of disease recurrence and its predictive factors. METHODS: A total of 169 patients with biopsy-proven EN or septal panniculitis from January 2008 to September 2018 were retrospectively reviewed. Patients were classified as either idiopathic or secondary EN. Patients' general information, clinical manifestations, investigations, and recurrence of EN were recorded. The details on histopathological findings were reviewed by a blinded dermatopathologist. RESULTS: The mean age at diagnosis of EN was 40.6 ± 17.3 years. The majority of patients (85.2%) were female. Idiopathic EN was found in 62.7% of patients. Tuberculosis (23.8%) and drugs (23.8%) were the leading causes of secondary EN. In univariate logistic regression analysis, lesions on upper extremities (p = 0.018), fever (p = 0.003), clinical lymphadenopathy (p < 0.001) favored secondary EN. Histopathologically, the presence of focal peripheral lobular panniculitis with eosinophils was linked to idiopathic EN (p = 0.03). However, multivariable logistic regression analysis failed to demonstrate factors associated with secondary EN. Recurrence was found in 46.6% of patients with no identifiable predictive factors. CONCLUSION: Although no clinical risk factors were associated with the etiology of EN, the histopathological presence of eosinophils in focal peripheral lobular panniculitis suggested idiopathic EN.