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Synonyms: Jadassohn's naevus phakomatosis
This is thought to be a variant form of sebaceous naevus (naevus sebaceous) and is a hamartomatous tumour characterised by hyperplasia of the epidermis and/or its associated components.They may present in a variety of forms - Becker's naevus, verrucous epidermal naevus, inflammatory linear verrucous epidermal naevus, naevus comedonicus, eccrine naevus, apocrine naevus and white sponge naevus.
They are classified according to clinical morphology, site and extent of involvement as well as the predominating epidermal structure within the individual lesion. If there are extensive epidermal naevi then they can be associated with extradermal abnormalities as part of the epidermal naevus syndrome (ENS). These are a heterogeneous group of disorders characterised by the presence of:
- One or more congenital hamartomatous ectodermal naevi of the skin.
- Other organ involvement - commonly brain or skeleton.
- Sebaceous naevi are relatively common among ENS.
- Skin lesions are salmon or yellow in colour and waxy.
- Epilepsy and intellectual impairment may be associated.
- Secondary tumours may occur in about 25% of naevus sebaceous, most of which are benign (eg, trichoblastomas, syringocystadenoma papilliferum or other basaloid proliferations), although malignant tumours can occur.
Keratinocytic epidermal naevus
- Again, relatively common.
- Pink or hyperpigmented plaques.
- Intellectual impairment, structural brain abnormalities, skeletal abnormalities and strabismus are reported.
- Skin lesions are localised collections of dilated follicles containing keratin, which may become infected or inflamed.
- Electroencephalogram (EEG) abnormalities, cataracts and skeletal abnormalities are reported.
Congenital hemidysplasia, ichthyosiform naevus and limb defects syndrome
Synonym: congenital unilateral ichthyosiform erythroderma
- CHILD = Congenital Hemidysplasia, Ichthyosiform Naevus and Limb Defects.
- Skin lesions are unilaterally inflammatory, reddened patches which may have dry scales; they are often located in the skinfolds.
- Ipsilateral hypoplasia of limbs can occur; the axial skeleton may also be affected.
- EEG abnormalities and hemispheric brain hypoplasia and cardiac abnormalities are reported.
Becker's naevus (pigmented hairy epidermal naevus)
- Becker's naevus is a patch of hyperpigmentation and hypertrichosis, which is androgen-dependent and so becomes more prominent after puberty in males; it is usually located on the shoulder.
- Onset is usually in late childhood/adolescence.
- It is associated with skeletal abnormalities, underlying muscle hypoplasia and ipsilateral hypoplasia of the breast.
- Variable clinical features, characterised by overgrowth of multiple tissues.
- CNS involvement is not typical but seizures and intellectual impairment have been reported.
- Other possible features are ovarian or parotid tumours, lipomas and vascular malformations.
- There are diagnostic criteria.
- A speckled lentiginous naevus associated with an epidermal naevus. The melanocytic component usually follows a segmental pattern ('checkerboard pattern') rather than following the lines of Blaschko.
- There may be neurological, ocular and skeletal abnormalities.
- Hemiatrophy with muscle weakness is common.
Inflammatory linear verrucous epidermal naevus
- Skin lesions are linear, pruritic, reddened and hyperkeratotic papules or plaques.
- Usually unilateral on the lower half of the body, often the buttock.
- Often presents at <6 months of age.
- May resemble psoriasis.
- There may be associated skeletal abnormalities, although this point has been questioned.
Porokeratotic eccrine naevus
- Verrucous, keratotic papules on the palms and soles.
- There may be widespread cutaneous involvement.
The lesions probably arise from abnormal ectodermal cells in the embryo. Ectodermal cells give rise to the skin epidermis and to neural tissue. Mosaicism seems to be involved, ie there are genetically different cell lines in one individual, and the abnormal cells give rise to the lesions.
A detailed review of the genetic basis and pathogenesis of ENS is available.
Epidermal naevi (with or without other organ involvement) have an incidence of around 2 per 1,000 live births. Epidermal naevus syndromes are all very uncommon, without reliable population incidence figures. Of patients with epidermal naevi, 10-30% may have disorders in other organs suggesting an ENS.[9, 10]
- Their most common forms are probably the sebaceous naevus (affecting the scalp), and the verrucous epidermal naevus. This has the appearance of verrucous papules that coalesce to form well-demarcated papillomata, ranging in colour from that of the surrounding skin to much more deeply pigmented.
- They may be congenital lesions, or develop during the early years of life. They tend to grow during childhood and then stabilise during the teenage years.
- They may be localised to a small area or occur in more diffuse forms. They are often arranged in a linear fashion along skin tension lines or the lines of Blaschko (purported lines of epidermal growth derived from clonal tissue patterns thought to be formed in embryo).
- The lesions themselves are usually asymptomatic apart from their appearance. However, inflammatory linear verrucous epidermal naevus lesions may be inflamed and irritated; naevus comedonicus lesions may become infected or inflamed.
In ENS, neurological involvement may include:
- Epilepsy or infantile spasms.
- Intellectual impairment.
- Structural or vascular brain abnormalities.
- Spinal lesions.
Skeletal involvement includes:
- Incomplete formation of bony structures - eg, spina bifida.
- Hypoplasia of bones.
- Bony cysts.
- Asymmetry of the skull or spine.
- Spontaneous fractures and rickets.
Ophthalmic involvement includes:
- Corneal opacities.
- Retinal changes.
- Various other ocular abnormalities which have been described.
Endocrine features have been reported:
- Hypophosphataemic vitamin D-resistant rickets has occurred in a number of cases.
- Precocious puberty has been described in several cases.
- Syndrome of inappropriate antidiuretic hormone (SIADH) has been reported in one case.
- Sebaceous naevus.
- Naevus syringocystadenomatosus papilliferus.
- Juvenile xanthogranulomata.
- Solitary mastocytoma.
- Multiple melanocytic naevi.
- Other skin and CNS lesions - eg:
Initial assessment, to include exclusion of an ENS:
- Full developmental and family history.
- Careful examination of all skin lesions. Skin biopsy may be required.
- Neurological examination.
- Ophthalmic examination.
- Assess skeleton, symmetry and gait.
Consider if further assessment is required:
- Generally, children with small epidermal naevi and no other findings do not need further investigation, although skin biopsy should be considered.
- Large epidermal naevi, especially in the head and neck, may merit CNS assessment.
- Epidermal naevi should be fully assessed if there is a suspected syndrome involving other organs.
These should be based on the needs of the individual patient but may include:
- Skin lesions should be referred for dermatological assessment and/or biopsied to ascertain their nature.
- CT/MRI are used to assess the presence/degree of any intracerebral or intraspinal lesions.
- Plain X-rays - eg, skull X-ray, CXR or skeletal survey.
- Biochemistry and endocrine investigations: these may be appropriate - eg, renal function, electrolytes, calcium and phosphate.
- Depending on the location and size of the lesions, excision may be merited for cosmetic reasons; however, this may not be feasible if underlying structures are involved.
- Other possible treatments are:
- Laser treatment may be successful in some cases.
- Topical vitamin D (calcipotriol) may be helpful in treating inflammatory linear verrucous epidermal naevus, although there is conflicting evidence about its effectiveness.
- 5-fluorouracil was used with good results in one case of a large linear epidermal naevus.
- Tacrolimus and fluocinonide, in combination, were successfully used in one case of inflammatory linear verrucous epidermal naevus.
- Shave excision followed by phenol peeling was used with good outcome in one case of verrucous epidermal naevus.
- If there is new growth of the skin lesion, excisional biopsy may be indicated to rule out malignancy.
- Anticonvulsants for epilepsy.
- Neurosurgery has been used in a few selected cases to control epilepsy.
- Poor cosmetic appearance.
- Inflammation of the lesion in certain forms (inflammatory linear verrucous epidermal naevus).
- Benign or malignant tumours arising within the lesion.
The prognosis is very good. They have the potential to have benign appendageal tumours arise within them (often syringocystadenoma papilliferum), or to transform into malignant tumours such as basal cell carcinoma or squamous cell carcinoma.
The lifetime risk of malignant transformation in sebaceous naevi is thought to be less than 1%. Malignant transformation of the lesion is rare before adolescence/adulthood. Verrucous epidermal naevi seem to have a much lower chance of forming tumours.
Further reading and references
Brandling-Bennett HA, Morel KD; Epidermal nevi. Pediatr Clin North Am. 2010 Oct57(5):1177-98.
Epidermal Nevus; DermIS (Dermatology Information System)
Sugarman JL; Epidermal nevus syndromes. Semin Cutan Med Surg. 2007 Dec26(4):221-30.
Flores-Sarnat L, Sarnat HB; Phenotype/genotype correlations in epidermal nevus syndrome as a neurocristopathy. Handb Clin Neurol. 2015132:9-25. doi: 10.1016/B978-0-444-62702-5.00002-0.
Asch S, Sugarman JL; Epidermal nevus syndromes. Handb Clin Neurol. 2015132:291-316. doi: 10.1016/B978-0-444-62702-5.00022-6.
Happle R; The group of epidermal nevus syndromes Part I. Well defined phenotypes. J Am Acad Dermatol. 2010 Jul63(1):1-22
Aslam A, Salam A, Griffiths CE, et al; Naevus sebaceus: a mosaic RASopathy. Clin Exp Dermatol. 2014 Jan39(1):1-6. doi: 10.1111/ced.12209.
Mi XB, Luo MX, Guo LL, et al; CHILD Syndrome: Case Report of a Chinese Patient and Literature Review of the NAD[P]H Steroid Dehydrogenase-Like Protein Gene Mutation. Pediatr Dermatol. 2015 Nov-Dec32(6):e277-82. doi: 10.1111/pde.12701. Epub 2015 Oct 13.
Epidermal naevi; DermNet NZ
Vidaurri-de la Cruz H, Tamayo-Sanchez L, Duran-McKinster C, et al; Epidermal nevus syndromes: clinical findings in 35 patients. Pediatr Dermatol. 2004 Jul-Aug21(4):432-9.
Adams D, Athalye L, Schwimer C, et al; A profound case of linear epidermal nevus in a patient with epidermal nevus syndrome. J Dermatol Case Rep. 2011 Jun 65(2):30-3.
Blaschko's Lines; Whonamedit.com
Kishida ES, Muniz Silva MA, da Costa Pereira F, et al; Epidermal nevus syndrome associated with adnexal tumors, spitz nevus, and hypophosphatemic vitamin D-resistant rickets. Pediatr Dermatol. 2005 Jan-Feb22(1):48-54.
Lambert DA, Giannouli E, Schmidt BJ; Postpolio syndrome and anesthesia. Anesthesiology. 2005 Sep103(3):638-44.
Mutasim DF; Successful treatment of inflammatory linear verrucous epidermal nevus with tacrolimus and fluocinonide. J Cutan Med Surg. 2006 Jan-Feb10(1):45-7.
Loddenkemper T, Alexopoulos AV, Kotagal P, et al; Epilepsy surgery in epidermal nevus syndrome variant with hemimegalencephaly and intractable seizures. J Neurol. 2008 Nov255(11):1829-31. Epub 2008 Nov 13.
Aguayo R, Pallares J, Casanova JM, et al; Squamous cell carcinoma developing in Jadassohn's sebaceous nevus: case report and review of the literature. Dermatol Surg. 2010 Nov36(11):1763-8. doi: 10.1111/j.1524-4725.2010.01746.x.