Seborrheic Dermatitis: Basic Facts

The Causes and Triggers of the Dermatitis of the Sebaceous Areas

Jan 13, 2009 Hanish Babu

Seborrheic dermatitis, the dermatitis of the sebaceous areas, is a common disease. It may be considered part of a clinical spectrum which include dandruff and psoriasis

Seborrheic dermatitis is a common skin disease associated with increased and altered sebum production and yeast colonization. Seborrheic dermatitis presents as a chronic dermatitis or eczema in sebum rich areas of the body like scalp, face and upper trunk. Its milder, non-inflammatory form is known as dandruff.

Seborrheic Dermatitis affects 1-3% general population, though dandruff is a very common occurrence. More than 36% of HIV positive patients have Seborrheic Dermatitis.

What are the Causes for Seborrheic Dermatitis?

Seborrheic dermatitis appears in genetically pre-disposed individuals with the so called seborrheic diathesis, meaning increased sebum secretion in the sebaceous gland rich areas of the body- the scalp, face, front of chest, and in between the shoulder blades. Certain triggering agents make the greasiness of the skin in these areas a flourishing ground for the yeasts known as malassezia. These yeasts breakdown and alter the composition of the sebum which further sets in motion an inflammatory response in the skin. This in turn increases the sebum secretion and the cycle continues again.

The skin becomes red, irritated and scaly. Itching is prominent in acute, active state. In addition to the classical sites, seborrheic dermatitis can also affect the eyelids, armpits, groin and gluteal fold.

Malassezia species M.restricta and M.globosa have been isolated from the seborrheic dermatitis skin.

Seborrheic dermatitis is seen in the first few months of life when maternal androgens are present in the blood. Then, the disease re appears in susceptible individuals after the sebaceous glands become active during puberty.

Seborrheic dermatitis can be considered a part of the clinical spectrum between dandruff and psoriasis.

What are the Triggers for Seborrheic Dermatitis?

1. Stress & Fatigue. Both lowered immunity and hormonal stimulation are the reasons for increased seborrheic dermatitis in stressed and fatigued conditions.
2. Hormonal Triggers . Androgen hormones control the sebaceous activity in humans. Probably these are under the control of a sebotrophic hormone secreted from the hypothalamus. Body builders using anabolic steroids get severe attacks of seborrheic dermatitis.
3. Environmental Triggers. Seborrheic dermatitis is precipitated in low humid conditions and in winter.
4. Low Immune states. Either due to medications, or diseases like HIV and malignancies trigger seborrheic dermatitis.
5. Food. Sugar consumption, fast foods, Vit B including B12 malutilization, biotin deficiency, niacin deficiency, pyridoxine deficiency, zinc deficiency and excess alcohol consumption have all been found to increase the incidence of seborrheic dermatitis .
6. Drugs. Broad spectrum Antibiotics, OCP, Systemic Steroids, buspirone, chlorpromazine, cimetidine, ethionamide, griseofulvin, haloperidol, interferon alfa, lithium, methoxsalen, methyldopa, phenothiazines, psoralens, stanozolol are some of the medications that have been found to increase seborrheic dermatitis. The list is not complete.
7. Diseases. Seborrheic dermatitis may be the presenting feature of Parkinsonism and HIV infection. Incidence of seborrheic dermatitis is high in epilepsy, idiopathic post encephalitis, diabetes mellitus, paralytic states etc.

What are the Other Causes for Itchy Scalp?

Seborrheic dermatitis has to be differentiated from scalp dryness, contact allergy and psoriasis, all of which cause itchy and scaly scalp.

What are the Types of Seborrheic Dermatitis?

1. Infantile Seborrheic Dermatitis
   • Craddle cap
   • Trunk: Flexural, napkin (diaper) area
   • Leiner’s disease
2. Adult Seborrheic Dermatitis
   • Scalp: Dandruff and inflammatory types.
   • Face: Inflammatory and non inflammatory, with blepharitis(eye lid)
   • Trunk: Petaloid, pityriasiform, follicular, follicular, eczematous type
   • Generalized exfoliative erythroderma

What are the Complications of Seborrheic Dermatitis?

1. Psychosocial impact: Chronic visible disease may affect a person's self esteem.
2. Secondary bacterial infection with Staphylococcus aureus may occur, with typical impetigo with increased redness, oozing and crusting.

What is Leiner’s Disease?

Leiner's disease is a complication of seborrheic dermatitis in infants with C5 complement deficiency. There is usually a sudden confluence of lesions leading to a generalised scaling and redness of the skin. The child is severely ill with anemia, diarrhea and vomiting. Secondary bacterial infection is common.

Related Reading

• How to Get Rid of Seborrheic Dermatitis?
• How to Get Rid of Dandruff

Reference

• Eczema, in Rook’s Textbook of Dermatology, 7th Edition, 2004

The copyright of the article Seborrheic Dermatitis: Basic Facts in General Medicine is owned by Hanish Babu. Permission to republish Seborrheic Dermatitis: Basic Facts in print or online must be granted by the author in writing.

Seborrheic Dermatitis Face: Non-Inflammatory	Seborrheic Dermatitis: Basic Facts	Malassezia & Seborrheic Dermatitis
Seborrheic Dermatitis Face: Inflammatory	Seborrheic Dermatitis Chest

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Comments

Jun 26, 2009 5:38 PM

Guest :

I have had seborrheic dermatitis for almost 10 years now. I went to a hematologist "blood disorder doctor" and found out that I had "folic acid deficiency anemia". I then began treatment of a "prescription" of folic acid. Within a week, I could tell that it was healing. That was over a year ago and I must say it has been quite painful and debillitating spending hours when my head was going through what I called a "breakout". The pain was so extreme that I thought I was going to have to go to the hospital.

I now am still healing VERY, VERY slowly and hopefully in the end will heal completely.

I recommend the following to help alleviate the pain and discomfort:

1) Paul Mitchell's Tea Tree Oil Shampoo/Conditioner. Apply and leave it in.

2) AmLantin Moisturizing Body Cream which does have 12% lactic acid which is an alpha-hydroxy acid which helps to exfoliate the skin quicker. Expensive but worth it.

3) Sarna Moisturizing Lotion with menthol. A little pricey but again a nice refreshing relief of the itching.

4) Milk of Magnesia helps to dry up the irritated areas quicker but makes a messy head so I put a bandana over my head.

I do recommend if you think you have this condition, to "demand" to go to a hematologist. I had to somewhat argue with my regular physician but finally got an appointment and even though it has been EXTREMELY long and painful, I can actually go out without a baseball cap on most days.

Sylvia Hart
Lakeland, FL

Sep 24, 2009 9:45 PM

Guest :

My derm gave me a jar of 10% glycolic acid cream, to even out the discoloration that SD leaves behind when it goes into remission (I'm not Caucasian).

I have SD on my face, chin, neck, occasionally chest. It's most bothersome on my face, chin and neck.

The regimen he has me on---cleaning morning and night with Cerave LOTION (not the cleaner), using Protopic ointment twice daily, and Clenia cream at night only---has given me my face back.

He also has me using Cerave cream to moisturize my face when needed.

My face is so dry and sensitive that he has me using only a wet washcloth to exfoliate while washing with the Cerave lotion. I find this really helps with the scales that build up on the SD areas and makes the face look way less "rough" and way smoother.

My question is, how does the glycolic acid 10% restore skin tone? Like, how does it work on the skin to even out the color? I've never used any of the "acids" before. I have to be really careful not to touch or unconsciously scratch my face before applying it, because it BURNS. And if I'm having an active flare on my face, I can't apply it all because it's AGONY. Thanks in advance.

Sep 25, 2009 12:00 AM

Hanish Babu :

Glycolic acid is the most popular among AHAs(Alpha Hydroxy Acids) used in sun damaged and ageing skin.Its action is multifacted- peeling, reduced melanin syntheisis, enhanced melanin dispersion and increased collagen and ground substance synthesis in the dermis through the stimulation of fibroblasts.The overall effects are evening out the skin tone and rejuvenation of the skin texture.

These are not to be applied on raw or inflammed skin.

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