top of page
Search

Blaschko's Lines

  • Writer: Polelo Mawela
    Polelo Mawela
  • Jul 27, 2022
  • 4 min read

Updated: Jul 28, 2022

Do Humans Have Stripes?


This article aims to increase health practitioners' awareness about Blaschko's lines, its manifestation in certain medical conditions, and the importance of skin examination.


Figure 1: Blaschko's lines (12)


Okay, not precisely stripes, the lines of Blaschko are a pattern of lines on the skin that represent the developmental growth pattern during epidermal cell migration. The lines are distinguished from other morphological lines of the skin and do not represent vascular, lymphatic or nervous structures. All humans are suspected to have Blaschko's lines which are invisible to the naked eye. These patterns may however become visible in certain skin conditions such as linear sebaceous naevus, unilateral naevoid telangiectasia and in other acquired skin conditions such as lichen striatus and linear psoriasis where they may persist for 1 to 2 years (2).


When visible, Blaschko's lines can be S-shaped, V-shaped, wavy, striped or linear (1). They are speculated to develop during the embryonic stage, but their origin is still not fully understood (3). The pattern itself could be created because specific cells or groups of cells react differently to certain skin conditions.


The German dermatologist Dr Alfred Blaschko conceptualised these skin patterns more than a century ago, it is however Dr Douglas Montgomery, an American dermatologist who first proposed that the linear pattern of epidermal nevi reflects “streams” of tissue growth during embryogenesis. He hypothesised that skin conditions that followed the Blaschko lines are manifestations of cutaneous mosaicism where there’s clinical contrast between genetically normal and abnormal skin(1). This pattern can be observed in congenital skin conditions such as adrenal hypoplasia, CHILD syndrome, albinism death syndrome and Menkes syndrome (4).



Figure 2: Patterns of the skin according to Blaschko's lines. (a) Type 1a: linear (many X-linked traits). (b) Type 1b: broad linear (many X-linked traits). (c) Type 2: lateralization or checkerboard pattern (as in congenital hemidysplasia with Ichthyosiform erythroderma and limb defects (CHILD) syndrome, for example). (d) Type 3: phylloid (leaf-like) pattern (11)


What Does The Pattern Look Like?

The pattern may appear as hyperpigmentation or skin lesions depending on the underlying medical condition. It tends to be V-shape over the upper spine, S-shape on the abdomen and an inverted U-shape from the chest to the upper arm. Vertical lines run along the front and back of the lower extremities. Blaschko's lines are less visible at the head and neck, and there are added lines on the posterior scalp [5].

The Importance of Blaschko’s

Blaschko’s pattern can appear in many dermatoses (any skin defect or lesion on the skin) (9) and in some neurological diseases (10), It therefore has the potential to help in the diagnosis of some medical conditions. In a neurological disease such as epilepsy, some case reports on diagnosed newborns show the appearance of hypopigmented whorls (following Blaschko's pattern) on the trunk and /or extremities of their bodies (6)(7)(8). For a condition like nonspecific spongiotic dermatitis, case reports show that it can appear as lesions on the chest, back and upper limbs (9).


Blaschko’s line patterns are not fully understood; most research is old, and little progress has been made since they were first discovered, yet the link to other conditions sparks interest in further research.


To keep updated and achieve your continuous professional development goal, visit ClinLib and Subscribe: www.clinlib.com


Figure 3: Lichen Planus (12)


Figure 4: Inflamed linear verrucous epidermal naevus (12)




Figure 5: McCune-Albright syndrome (12)


Reference:


  1. Molho-Pessach V, Schaffer J. Blaschko lines and other patterns of cutaneous mosaicism. Clinics in Dermatology. 2011;29(2):205-225. available from: https://www.sciencedirect.com/science/article/abs/pii/S0738081X10001641?via%3Dihub

  2. JACKSON R. The lines of Blaschko: a review and reconsideration. British Journal of Dermatology [Internet]. 1976 [cited 22 July 2022];95(4):349-360. Available from: https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-2133.1976.tb00835.x

  3. Abyaneh M, Griffith R, Falto-Aizpurua L, Nouri K. Famous Lines in History. JAMA Dermatology [Internet]. 2014 [cited 22 July 2022];150(10):1062. Available from: https://jamanetwork.com/journals/jamadermatology/article-abstract/1912373

  4. Sun B, Tsao H. X-Chromosome Inactivation and Skin Disease. Journal of Investigative Dermatology [Internet]. 2008 [cited 22 July 2022];128(12):2753-2759. Available from: https://pubmed.ncbi.nlm.nih.gov/18509358/

  5. Tagra S, Talwar A, Walia R. Lines of Blaschko. Indian Journal of Dermatology, Venereology and Leprology [Internet]. 2005 [cited 22 July 2022];71(1):57. Available from: https://www.semanticscholar.org/paper/Lines-of-Blaschko.-Tagra-Talwar/cc431a31a15d95361ff82e11b6f566f86ed7dd0f

  6. Madaan P, Rao Pala N, Saini L. An infant with epilepsy: don't forget the importance of skin examination. BMJ Case Reports [Internet]. 2019 [cited 22 July 2022];12(8):e231818. Available from: https://casereports.bmj.com/content/12/8/e231818

  7. Sharawat I, Panda P. Epileptic Spasms in an Infant with Incontinentia Pigmenti: Report of a Rare Case with Brief Review of the Literature. Journal of Neurosciences in Rural Practice [Internet]. 2020 [cited 22 July 2022];11(02):325-328. Available from: https://www.thieme-connect.de/products/ejournals/abstract/10.1055/s-0040-1709246

  8. Sharawat I, Panda P. Epileptic Spasms in an Infant with Incontinentia Pigmenti: Report of a Rare Case with Brief Review of the Literature. Journal of Neurosciences in Rural Practice [Internet]. 2020 [cited 22 July 2022];11(02):325-328. Available from: https://pubmed.ncbi.nlm.nih.gov/32367988/

  9. E G, L M. [Blaschkitis in adults] [Internet]. PubMed. 2022 [cited 22 July 2022]. Available from: https://pubmed.ncbi.nlm.nih.gov/2181911/

  10. Pavone P, Praticò A, Ruggieri M, Falsaperla R. Hypomelanosis of Ito: a round on the frequency and type of epileptic complications. Neurological Sciences [Internet]. 2015 [cited 22 July 2022];36(7):1173-1180. Available from: https://pubmed.ncbi.nlm.nih.gov/25586695/

  11. Primary Care Dermatology Society. Blaschko’s lines. LAST UPDATED: Aug 26, 2021.Can be found on: https://www.pcds.org.uk/clinical-guidance/blaschkos-lines

  12. Dermnet NZ. Blaschko’s lines. 2008. Can be accessed here: https://dermn (12 etnz.org/topics/blaschko-lines





 
 
 

Comments

bottom of page