Query: Nevus comedonicus

title: Nevus Comedonicus With Acne Vulgaris and Obesity.
abstract: Nevus comedonicus is a rare hamartoma of the pilosebaceous unit, first described by Kofmann in 1895  In most cases it is present at birth but may also develop later, usually before the age of 10 years, without racial or sexual preponderance. When appearing in adults, although rare, it is frequently associated with irritation or trauma [2] The lesions typically present a linear or zosteriform distribution, but extensive areas have already been described, including variant with bilateral involvement. The most frequently affected sites are the face, trunk, neck, and upper limbs. It may affect areas without hair follicles, such as the palms, soles, and the glans penis. Scalp involvement is rare  There may be associations with other skin lesions or abnormalities of the central nervous, musculoskeletal, and ocular system  We present a case of nevus comedonicus in a woman suffering from obesity and acne vulgaris.

title: Bilateral nevus comedonicus of the eyelids: An unusual cause of ptosis and ectropion
abstract: Nevus comedonicus is a rare developmental abnormality of the infundibulum of the hair follicle.  We report here an unusual case of bilateral extensive nevus comedonicus of the eyelids complicated by bilateral ptosis and ectropion of the lower eyelids. Blepharoplasty was performed on both upper eyelids. Histopathological findings on skin biopsy typically show large, grouped, dilated follicular ostia filled with keratin.  This case is unusual as regards the late onset (lesions first appeared at age 35) and location of the nevus comedonicus on both eyelids.

title: Further delineation of the phenotypic spectrum of nevus comedonicus syndrome to include congenital pulmonary airway malformation of the lung and aneurysm
abstract: Nevus comedonicus syndrome (NCS) is a rare epidermal nevus syndrome characterized by ocular, skeletal, and central nervous system anomalies. We present a 23 month old boy with a history of a congenital pulmonary airway malformation (CPAM) of the lung and a congenital cataract who developed progressive linear and curvilinear plaques of dilated follicular openings with keratin plugs (comedones) on parts of his scalp, face, and body consistent with nevus comedonicus. MRI of the brain demonstrated an aneurysm of the right internal carotid artery. Genetic testing identified NEK9 c.1755_1757del (p.) at mean allele frequency of 28% in the nevus comedonicus. This same mutation was present in the CPAM tissue. This is the first case of a CPAM in a patient with an epidermal nevus syndrome. This case expands the phenotype of nevus comedonicus syndrome to include CPAM and vascular anomalies.

title: Nevus Comedonicus Suppurativa: A Report of a Novel Entity.
abstract: Nevus comedonicus and hidradenitis suppurativa (HS) are disorders of the pilosebaceous unit sharing a similar pathogenesis of follicular occlusion. To our knowledge, less than 10 cases of HS like lesions complicating nevus comedonicus have been reported. We describe a six year old female child with congenital linear nevus comedonicus in the left axilla and groin, complicated by recurrent HS like lesions in the two years prior to presenting to our clinic. After a meticulous review of the literature, we propose a novel term, nevus comedonicus suppurativa, for this clinical entity.

title: Improvement of nevus comedonicus after repeated microneedling
abstract: Nevus comedonicus is a rare, benign hamartoma characterized by closely arranged, honeycomb like dilated follicular openings with black or brown keratinous plugs typically affecting the face, neck, upper arms, chest, or abdomen.1,2 It can occur congenitally or develop later in life, most commonly diagnosed at the age of approximately 10 years. Standard treatment options include topical corticosteroids, salicylic acid, ammonium lactate, topical and oral retinoids, and laser treatments. However, complete resolution is usually not achieved by these treatments, and relapses are common. Surgical excision has shown good aesthetic results in localized nevus comedonicus and is noted as the best option for cure.2 We used microneedling as a minimally invasive treatment option for our patient. Although there is one prior case of microneedling using a fractional radiofrequency device reported to treat nevus comedonicus, to our knowledge microneedling without radiofrequency has never been reported or studied as a treatment option for nevus comedonicus.3 A single treatment using a radiofrequency device can cost up to $1000, and this device is less readily available to most providers. We report a case of nevus comedonicus that responded favorably after receiving treatment with the novel method of microneedling combined with salicylic acid peel.

title: Unilateral nevus comedonicus associated with epidermoid cyst
abstract: Nevus comedonicus (NC) is a type of an epidermal nevus which was first described in 1895 by Kofmann. Clinically, it is characterized by linear lesion comprising numerous dilated follicular openings with keratinous plugs resembling classical comedones, seen mainly on the head and neck area followed by trunk and upper arm. Treatment options of NC include topical therapy, laser, and surgery. NC associated with epidermoid cyst is rare. We report here a case of NC affecting left side of trunk, left lower limb with epidermoid cysts.

title: Dermoscopy of late onset nevus comedonicus
abstract: Nevus comedonicus (NC) is a rare hamartoma of the pilosebaceous unit, a subtype of epidermal nevus first described by Kofmann in 1895.1 NC manifests with linear or grouped papules and dilated follicular openings with keratotic plugs (resembling comedones) particularly on the face, trunk, and neck; in 50% of cases, it is present at birth, but can also develop during childhood (most commonly before the age of 10 years) The rare presence of skeletal and neurological abnormalities describes the nevus comedonicus syndrome.2 Histopathology shows keratin filled invaginations of the epidermis, with absent or rudimentary sebaceous glands. Inflammation and subsequent dermal infiltrate have been described in some cases.2 Rarely, NC may present in adults;recently Zaniello et al. reporting an additional case of late onset NC, reviewed the few cases described.3 A 72 year old man with a previous history of stage IB cutaneous melanoma on the trunk in 2013 and prostate carcinoma presented in June 2019 with a keratotic plaque (2 x 1 cm in diameter) and a small comedo like nodule (almost 1 cm in diameter) on the left calf, following a Blaschko line  The lesions had appeared almost 25 years before, and the patient had been asymptomatic until the week before, when the lesions became very itchy. Dermoscopic examination showed a central keratotic plug surrounded by a white structureless area with scales and focal pale structureless red area without clear vessels  The patient had been taking candesartan, hydrochlorothiazide, bicalutamide, simvastatine, and rabepreazole for years. General physical and neurological examinations were normal, and the patient denied a family history of analogous lesions. Histopathology demonstrated a cyst dilated follicular opening filled with keratin, slight acanthosis of the epidermis, and hyperkeratosis with orthoand parakeratosis. The follicular epithelial wall and the epidermis showed EHK with hypereosinophilic keratohyalin granules in the granular cell layer and perinuclear vacuolization  Sebaceous and eccrine glands were not present. A focal discrete lymphohistiocytic infiltrate was

title: Bilateral nevus comedonicus of the eyelids: An unusual cause of ptosis and ectropion
abstract: In their article entitled " Bilateral nevus comedonicus of the eyelids: An unusual cause of ptosis and ectropion",1 which was published recently in your distinguished journal, we strongly believe the authors misdiagnosed the patient. What the article and the attendant figure show is a classic textbook example of Favre Racouchot syndrome (FRS) rather than nevus comedonicus (NC) Although FRS is a ubiquitous condition that predominantly affects the periocular region, it is unfortunate that the condition is under appreciated in the ophthalmic literature, which may have led some authors to confuse FRS with the far less prevalent but far more popular nevus comedonicus. With only around 200 cases of nevus comedonicus described in the literature, the condition is extremely rare, and usually manifests at birth or before the age of 10 years.2 5 Although acquired cases of NC have been described, these lesions are typically hereditary.2 5 The exact etiology is unknown, however, it is generally categorized as a congenital hair follicle deformity (a hamartomatous malformation caused by an imperfect development of the folliculosebaceous unit) caused by somatic mutations in the NEK9 gene (OMIM 617025, 14q24.3) a gene which is believed to be involved in follicular homeostasis.5,6 Abnormalities in FGFR2 signaling (OMIM 176943, 10q26.13) have also been implicated in comedogenesis in NC patients.6,7 The condition is characterized by the aggregation of dilated follicular orifices filled with keratinous material (open and closed comedones) which are usually grouped in linear streaks or distinct bands. These lesions generally follow Blaschko's lines which are the lines that are thought to map the pattern of migration of epidermal cells during fetal development  Racouchot syndrome (nodular elastosis with cysts and comedones) is a fairly common cutaneous disorder which is largely predisposed to by prolonged sun exposure and ultraviolet damage (UV B, or UV A1) smoking, radiation therapy, and topical or systemic steroids.9,10 With an overall prevalence of 1.4% in adults aged between 25 and 74 years, a 6% prevalence in patients aged between 40 and 60 years, and a prevalence of 2.5% among agricultural workers,9,11,12 Favre Racouchot syndrome is a ubiquitous condition and is far more common than nevus comedonicus which is indeed rare with a prevalence of 1/45,000 1/100,000.13 The onset of Favre Racouchot syndrome is usually delayed (middle old age) and the condition is typically bilateral, although the distribution may be asymmetric if one side of the face is unevenly exposed to the sun.5,9,10 Although multiple comedones are a feature of both conditions, the typical appearance in patients with FRS is the presence of bilateral discrete follicular orifices plugged by keratotic material, which usually occur in groups or clusters of variably sized nodules that have an elevated margin and an eccentric opening or pore that is predominantly filled with black material (blackheads).9,10 The comedones in Favre Racouchot syndrome do not follow Blaschko's lines, but they have a predilection for the lateral canthal region, and the malar eminence is usually involved as well. The surrounding skin usually shows classic unmistakable signs of severe actinic damage (yellowish skin discoloration, variable pigmentation, and severe wrinkling) which is an essential feature of the condition  The age of presentation of the patient in question strongly argues against a diagnosis of nevus comedonicus. In addition, the accompanying figure shows classic unambiguous signs of severe actinic damage, amidst which the comedo lesions are distributed, and they do not follow any particular linear pattern at all. The peculiar facial features of the Favre Racouchot syndrome are so unique that is difficult to misdiagnose a patient with this condition,10 yet both conditions are nearly identical histopathologically except for the presence of evidence of solar elastosis in FRS

title: Dermoscopy of nevus comedonicus: A case series
abstract: Nevus comedonicus (NC) is an uncommon condition which belongs to the spectrum of the epidermal nevi syndrome. Dermoscopy is a non invasive tool which can help to rule out other differential diagnoses, making it especially valuable in pediatric cases. We present three children with NC and describe their dermoscopic findings.

title: The Follicular Impaction nevus Comedonicus