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Integumentary system ORGAN SYSTEMS

Dandruff

Light, white to yellow and dispersed flaking on the scalp and hair without erythema and with absent/mild pruritus.

Introduction

Light, white to yellow and dispersed flaking on the scalp and hair without erythema and with absent/mild pruritus.

  • Affects half of world population
  • Mildest form of seborrhoeic dermatitis (SD)

Aetiology

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Malassezia species cultured in modified Dixon broth. A, M globosa; B, M restricta; C,M furfur. (Original magnification: 3600.) | Gupta, A.K., Batra, R., Bluhm, R., Boekhout, T., & Dawson, T. (2004). Skin diseases associated with Malassezia species. Journal of the American Academy of Dermatology, 51 5, 785-98.

Disease associations (excessive dandruff):

  • Seborrhoeic dermatitis
    • Skin condition associated with an overgrowth of yeast on the skin, which can cause the scalp, face and other areas of the body to become scaly, itchy and red
  • Tinea capitis
    • Fungal infection of the scalp, also called scalp ringworm
  • Eczema
    • Skin condition that causes the skin to become dry, red, flaky and very itchy
  • Allergic contact dermatitis
    • Reaction to products used on the scalp, such as hair dye, hairspray, hair gel or mousse
  • Psoriasis
    • Skin condition that causes red, flaky, crusty patches of skin covered with silvery scales
srep24877-f4
The shape of the nodes corresponds to the type of each factor. The color of the edges corresponds to the positive (red), negative (blue) or sole effect (black) relationship. The shape of edges corresponds to the interaction (↔) or effect (→) of the relationship. The full line of the edges corresponds to P 0.05. | Xu, Z., Wang, Z., Yuan, C., Liu, X., Yang, F., Wang, T., … Zhang, M. (2016). Dandruff is associated with the conjoined interactions between host and microorganisms. Scientific Reports, 6, 24877. Retrieved from https://doi.org/10.1038/srep24877

Physiology

Factors responsible for dandruff production:

  • Sebum or sebaceous secretions of skin
  • Metabolic by-products of skin commensals (most specifically Malassezia yeasts)
  • Individual susceptibility and allergy sensitivity

Dandruff scale

Cluster of corneocytes (protein complex that is made of tiny threads of keratin in an organised matrix), which have retained a large degree of cohesion with one another and detach as such from the surface of the stratum corneum.

  • Size and abundance of scales are heterogeneous from one site to another and over time
  • Parakeratosis (mode of keratinization characterized by the retention of nuclei in the stratum corneum) is seen in the plaques of psoriasis and in dandruff.
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Scanning Electron Microscope (SEM) picture of freshly prepared human dandruff sample. | Horoporo – CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=12028106

Diagnosis

Differential diagnosis

Seborrheic dermatitis:

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Dandruff (A) and seborrheic dermatitis (SD) (B) on scalp. Note larger, yellowish scale and scalp erythema in SD versus dandruff. | Gupta, A.K., Batra, R., Bluhm, R., Boekhout, T., & Dawson, T. (2004). Skin diseases associated with Malassezia species. Journal of the American Academy of Dermatology, 51 5, 785-98.
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Comparison of seborrheic dermatitis and dandruff. | Borda, L. J., & Wikramanayake, T. C. (2015). Seborrheic Dermatitis and Dandruff: A Comprehensive Review. Journal of Clinical and Investigative Dermatology, 3(2), 10.13188/2373-1044.1000019. https://doi.org/10.13188/2373-1044.1000019

Management

Anti-dandruff substances:

  • Zinc pyrithione (coordination complex of zinc with fungistatic and bacteriostatic properties)
  • Salicylic acid (help remove outer layer of skin)
  • Selenium sulphide (antifungal agent)
  • Ketoconazole (broad spectrum antimycotic agent)
  • Coal tar (causes the skin to shed dead cells from the top layer and slows skin cell growth)

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