This case report explores a rare manifestation of Becker\'s nevus, where the patient exhibited an unusual dermatomal distribution featuring a hyperpigmented, irregular patch with associated hypertrichosis on the T4 segment. While Becker\'s nevus is a well-known dermatological condition typically observed in the upper back region, instances of dermatomal distribution are exceptionally uncommon. This case presents a unique occurrence of segmental Becker\'s nevus, highlighting the atypical presentation of this condition.

Pigmented hairy epidermal nevus, also known as Becker\'s nevus, has a typical description as a unilateral, hairy in appearance, light to dark brown patch with an irregular but clearly defined border. However, the exact aetiopathogenesis is still poorly comprehended. We report the case of a 19-year-old female who presented with asymptomatic brownish-pigmented macular lesions on the right breast that had slowly increased in size over the past three years. Upon cutaneous inspection, the right breast had 3-5 mm rounded and oval perifollicular macules that ranged from light to dark brown hue without increased hair growth. The macules were discrete and in no particular pattern. Dermoscopy of the lesions showed well-defined perifollicular hypopigmentation surrounded by a pigmented network-like pattern. Histopathology of a punch biopsy taken from one of the follicular lesions demonstrated an increase in basal layer pigmentation with elongation of rete ridges and acanthosis, consistent with Becker\'s nevus. The patient underwent three sittings of diode laser therapy, once in four weeks, with slight improvement in pigmentation.

Becker\'s nevus (BN) is a kind of epidermal cutaneous hamartoma. A noticeable hyperpigmented patch with a big, unilateral, hyperpigmented macule and irregularly shaped borders is the manner in which BN often presents. In this case, a 16-year-old boy has asymptomatic dark brown colored follicular macule on the left side of the cheek shortly after birth. The lesions were initially inconspicuous but gradually became darker as time passed. The macules on some of them grew hair. This case of BN with apparent hypertrichosis on one side of the cheek, which made it challenging to make a differential diagnosis with whiskers. The primary point of differentiation is that the lesions of BN only appear unilaterally. On the other hand, the face has whiskers on both sides. Additionally, BN will show hyperpigmentation whereas whiskers do not. In conclusion, for its unusual clinical presentation, we believe that reporting this case may help dermatologists avoid misdiagnosing similar cases.

Becker\'s nevus, also known as Becker\'s melanosis or Becker\'s pigmentary hamartoma, is a concurrent melanosis first described by S. William Becker. It is a type of acquired hyperpigmentation characterized by well-defined, unilateral lesions with regular borders. It is associated with hypertrichosis and hyperpigmented brownish patches with a mean diameter of 15 cm. The shoulder, scapular area, and upper arms are the most commonly affected areas, but it can occur on any area of the body, including the forehead, face, neck, lower trunk, extremities, and buttocks. The lesion usually appears around puberty, and males are more likely to be affected than females. A 27-year-old male of Arabic descent who was medically free presented to the dermatology clinic complaining of bilateral, symmetrical, hyperpigmented patches on the upper back. The lesions started almost at birth, gradually growing in size and darkening in color over time. On local skin examination, the lesions were bilateral, symmetrical, hyperpigmented patches on the upper back. They were both homogeneous and brown in color with irregular borders and blotchy hyperpigmented macules on both sides of the upper back associated with sparse hair development. Histopathological examination revealed epidermal hyperkeratosis, acanthosis, and focal regular elongation of rete ridges with clubbing. Increased basal layer pigmentation was noticed. The dermis showed focal areas with pigment incontinence. Based on the above clinicopathological findings, the patient was diagnosed with Becker\'s melanosis. He was referred to the laser clinic for further treatment.

Becker\'s nevus (BN) is a cutaneous hamartoma of benign nature that develops through adolescence and affects mostly young men. The nevus is usually located unilaterally and is characterized by hypertrichosis and hyperpigmentation. Despite recent advances in treatment modalities, no effective treatment has been established for BN hyperpigmentation. We sought to assess the efficacy and safety of fractional Erbium: YAG 2940 nm and Q-switched Nd: YAG 1064 nm lasers in the treatment of BN hyperpigmentation. Twenty-three patients with BN were included in a prospective, randomized-controlled, observer-blinded, split-lesion comparative technique trial. In each patient, two similar square test regions were randomized to either be treated with a fractional Erbium: YAG 2940 nm laser or with a Q-switched Nd: YAG 1064 nm laser. Each patient was treated with three sessions at six-week intervals. At the follow-up, clearance of hyperpigmentation was assessed by physician global assessment, visual analogue scale, grade of improvement, patient global assessment, and patient satisfaction. Regions treated with the fractional Erbium: YAG 2940 nm laser demonstrated significantly better improvement compared to ones treated with the Q-switched Nd: YAG 1064 nm (p-value = 0.001) laser. Adverse effects such as repigmentation and hypertrophic scarring were not reported during the follow-up period. The outcomes were cosmetically acceptable with overall high satisfaction among the included patients. Our data suggest a superior role for the fractional Erbium: YAG (2940 nm) laser in the treatment of BN hyperpigmentation compared to the Q-switched Nd: YAG (1064 nm) laser, along with being a safer method and having no reported side effects.

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Becker\'s nevus (BN) is a cutaneous hamartoma which is characterized by circumscribed hyperpigmentation with hypertrichosis. Recent studies have revealed that BN patients harbored postzygotic ACTB mutations, which were restricted to arrector pili muscle lineage. We screened for ACTB mutations in 20 Chinese patients with BN and found that recurrent mutations (c.C439A or c.C439T) in ACTB were detected in the majority of BN patients. However, more than 20% of the patients were negative for ACTB mutations, suggesting a possible genetic heterogeneity in Becker\'s nevus. Interestingly, these mutations were also detected in dermal tissues outside the arrector pili muscle. We further performed genotype-phenotype correlation analysis, which revealed that lesions above the waistline, including the trunk above the anterior superior spine level, upper limbs and face, or covering more than 1% BSA were more likely to be positive for ACTB mutations. Altogether, our results provide further evidence of postzygotic ACTB mutations in BN patients and suggest a possible genotype-phenotype correlation of BN.

Becker\'s nevus (BN) clinically presents as brown patches with hypertrichosis. The risk of pigmentary changes still remains a concern when using lasers to treat Asian patients with BN. We aimed to evaluate the outcomes on reduction of hairs and pigment of BN using the long-pulsed 1064-nm Nd:YAG (LPNY) and/or 755-nm alexandrite (LP-Alex), before treating pigment in earnest. A total of 13 subjects were treated with the LPNY (n = 8), the LP-Alex (n = 4), and both (n = 1). Improvements on hair removal and pigment reduction were assessed using a 5-point global assessment scale. Patient satisfaction was also assessed. Treatment parameters were within those commonly used for the purpose of epilation. The average follow-up period was 19.5 ± 12.3 weeks, and the mean total number of sessions was 2.0. Eleven subjects reported >50% improvement in hair removal (11/13, 86.7%), and pigment reduction of >50% improvement was observed in 9 subjects (9/13, 69.2%). Patient satisfaction showed >50% lesion clearance in 84.6%. Hair removal settings of LPNY and LP-Alex were effective in both hypertrichosis and pigment reduction in the initial strategy of treatment of BN in skin of color.

Becker\'s nevus is a relatively common skin lesion with brown hyperpigmentation and hypertrichosis. It may be expressed simultaneously with other cutaneous, muscular, or skeletal defects, such as hypoplasia of the breast or scoliosis, for which the term \"Becker\'s nevus syndrome\" has been proposed. An 8-year-old boy presented with a Becker\'s nevus on the right cheek, chin, and upper neck with alveolar bone hypertrophy in the anterior mandible, which led to an anterior crossbite and severe canting of the mandibular anterior teeth. Through orthopedic treatment using a face mask, the anteroposterior jaw relationship was improved. In phase 2 treatment, we corrected the canting of the mandibular anterior teeth with a segmental intrusion of the mandibular anterior right teeth into the hypertrophic alveolar bone area. The facial profile was improved along with acceptable occlusion, and the treatment result was stable at 1 year after the end of the treatment, without any periodontal attachment loss, root resorption of mandibular anterior teeth, or increase in the size of the hypertrophic region. This case report describes the successful comprehensive treatment of a growing patient with skeletal Class III malocclusion and multiple characteristics of Becker\'s nevus syndrome.

Becker\'s nevus is a common pigmented dermatosis, usually featured by ipsilateral pigmented patch with hypertrichosis. Becker\'s nevus is often treated with various types of lasers although other regimens are available. However, clinical outcomes appear inconsistent among studies. To summarize the clinical outcomes of Becker\'s nevus treated with lasers via literature review. A variety of lasers had been used alone or in combination to treat Becker\'s nevus. Laser wavelengths used for Becker\'s nevus ranged from 504 to 10,600 nm, while the number of treatment varied from 1 to 12 sessions. The clinical outcomes were mixed although combination of lasers with different wavelengths appeared to achieve a better efficacy. Adverse effects were usually mild to moderate erythema. While lasers are relatively safe, their efficacy for Becker\'s nevus is moderate. It seems that combination therapy could improve the outcome. However, trials in larger group of patients are required to validate the efficacy of each type of lasers for Becker\'s nevus.