Naevus simplex

Author: Wei Wu, Year 5 medical student, The University of Auckland, Auckland, New Zealand. DermNet NZ Editor-in-Chief: Adjunct Assoc. Prof. Amanda Oakley, Dermatologist, Hamilton, New Zealand.


What is naevus simplex?

Naevus simplex is a common, benign capillary vascular malformation. It presents at birth as a pink or red patch and is most often observed on the nape of the neck, eyelid, or glabella [1,2].

Naevus simplex is also called:

  • Salmon patch
  • Stork bite (when on the nape of the neck)
  • Angel’s kiss (when on the glabella and eyelids)
  • Naevus flammeus simplex.
Naevus simplex — the stork mark

Who gets naevus simplex?

Naevus simplex affects infants of all races and genders. It occurs in approximately 40% of Caucasian infants [3] and is less often observed in darker-skinned infants [1]. It affects male and female infants equally [4].

What causes naevus simplex?

The dermal capillaries in a naevus simplex are dilated due to delay in maturation after neuroectodermal migration and fusion during embryonic development. Reduced regulation by autonomic nerves may be a contributing factor [2,3].

What are the clinical features of naevus simplex? 

Naevus simplex is present at birth as a single or multiple, flat, pink or red patches, typically with an indistinct, irregular border and blanching on compression [1,2]. They become redder with crying, fevers, breath holding, straining, vigorous physical activity, and changes in ambient temperature [1,2,5]. They tend to become less prominent as the child gets older.

The skin lesions are usually midline [4] and can be bilateral and symmetrical [6]. They are most commonly found on the nape of the neck, eyelids and glabella [1]. They may also involve the forehead, scalp, nose, lips and back [2]. Naevus simplex is not painful or itchy [7].

The term ‘naevus simplex complex’ has been proposed for widespread lesions beyond the common sites [2].

Disease associations with naevus simplex

Midline lumbosacral naevus simplex is sometimes called a ‘butterfly-shaped mark’ and is occasionally observed in a baby with spinal dysraphism. Imaging studies looking for spinal dysraphism may be undertaken if there are other local skin changes such as excess hair growth (localised hypertrichosis), a dermal sinus or pit, a lipoma, or a deviated gluteal cleft, or many similar lesions elsewhere. Infants with a naevus simplex at this location often also have many similar lesions elsewhere [2,4].

Naevus simplex is occasionally observed in a baby with another condition, such as:

  • Beckwith-Wiedemann syndrome [2]
  • Macrocephaly-capillary malformation syndrome [2]
  • Odontodysplasia [2]
  • Nova syndrome [2]
  • Roberts syndrome [2]
  • Rubenstein-Taybi syndrome [1].

It is uncertain whether there is a true association with these syndromes [1,4].

How is naevus simplex diagnosed?

Naevus simplex can be diagnosed by its clinical appearance and no further testing is usually required [7].

What is the differential diagnosis for naevus simplex?

Naevus simplex is sometimes confused with naevus flammeus (port wine stain) or with infantile proliferative haemangioma (strawberry naevus) because these vascular lesions are also seen in infants.

Naevus flammeus

Naevus flammeus is a capillary vascular malformation found in 0.3% of newborn infants [1,6]. The lesions present as pink, red or purple patches and can be localised, extensive or multiple [1,6]. Unlike naevus simplex, naevus flammeus tends to be unilateral, often persisting, darkening and thickening with increasing age [1,6].

Infantile proliferative haemangioma

Infantile proliferative haemangioma is a vascular tumour found in 1.1–2.6% of newborn babies, rising to 10% by 1 year of age. It affects female infants more often than males. The haemangioma begins as a pink patch then enlarges. It is most commonly found on the head and neck but may arise on other body sites. Infantile proliferative haemangioma usually resolves after infancy but can leave a residual mark [1,6].

Vascular lesions in infants

What is the treatment and outcome for naevus simplex?

In most sites, naevus simplex fades and disappears within the first 1 to 2 years of life [2]. A lesion on the nape of the neck fades more slowly and incompletely, with a 50% chance of persisting indefinitely [1,5]. As it is often covered by hair, it may not be a cosmetic issue.

Pulsed dye laser therapy could be considered to lighten the colour of a persistent lesion [6].

Resolution of naevus simplex over time

 

Related information

 

References

  1. Freedberg I, Eisen A, Wolff K, Austen K, Goldsmith L, Katz S. Fitzpatrick's Dermatology In General Medicine. 6th ed. New York: McGraw-Hill Professional; 2003.
  2. Juern A, Glick Z, Drolet B, Frieden I. Nevus simplex: A reconsideration of nomenclature, sites of involvement, and disease associations. Journal of the American Academy of Dermatology. 2010 Nov;63(5):805-814. PubMed.
  3. Leung A, Telmesani A. Salmon Patches in Caucasian Children. Pediatric Dermatology. 1989 Sep;6(3):185-187. PubMed.
  4. Eichenfield L, Frieden I, Zaenglein A, Mathes E. Neonatal and Infant Dermatology. 3rd ed. Elsevier; 2014.
  5. Cohen B. Hemangiomas in Infancy and Childhood. Pediatric Annals. 1987 Jan;16(1):17-26. PubMed.
  6. McLaughlin M, O’Connor NR, Ham P. Newborn Skin: Part II. Birthmarks. Am Fam Physician. 2008 Jan;77(1):56-60. PubMed.
  7. Skinsight - Salmon Patch. Skinsight. 2018. Available at: https://www.skinsight.com/skin-conditions/infant/salmon-patch (accessed 19 March 2018)

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