Dandruff

Dandruff conditions appear as an excessive and visible scaling of the scalp. It is a chronic condition that develops by outbreaks and affects more men than women.
Dandruff conditions are common but they generally are an aesthetic and psychological problem: dandruff on clothing, hair not looking clean, endless itching feel in the scalp. The main complication of dandruff is it's recurrence.

• Dry dandruff is the most common form of dandruff. It presents with fine, dry, greyish flakes/scales distributed all over the scalp. The epidermis on the scalp is not inflamed but there may be itching (pruritus). The flakes do not stick to the scalp so the can easily fall onto clothing especially during hair brushing.
• Oily dandruff is the more moderate form of seborrheic dermatitis. The scales are larger in size, yellowish in color and much thicker and oilier than dry dandruff. The scales are stuck with sebum (oil) and are usually associated with hyperseborrhea (overproduction of sebum). This coat of oily scales, promotes irritation which can lead to inflammation and itching.

Seborrheic Dermatitis

Seborrheic dermatitis (oily dandruff) is a chronic inflammatory condition that is marked by flare-ups. It is very common and affects between 3-5% of the population. It can occur during various periods of life: infancy (cradle cap), adolescence and adulthood. While rare before puberty, it peaks between the ages of 18 and 40, with a strong predominance for men. After the age of 40, the incidence reduces but continues to mostly affect men.  Seborrheic dermatitis is a pathology in which the diagnosis is mostly clinical. This is a benign skin condition that affects the seborrheic areas of the body: scalp, face and thorax (the areas that are particularly rich in sebaceous (oil) glands and/or rich in keratin)

The "classic" clinical appearance of seborrheic dermatitis in adults is mainly characterized by the combination of 3 symptoms:

• Pruritus (itching)
• Erythema (red plaques)
• Desquamation (scales, dandruff)

Causes

Seborrhoeic dermatitis tends to be hereditary. However, the severity of flaking occur with stress, menstruation, hormonal fluctuations, illness, certain foods and sometimes the type of shampoo used.

Psoriasis

Psoriasis is benign dermatosis that affects approximately 2-5% of the population. This uncomfortable condition can occur at any age and equally affects both men and women. Psoriasis presents as red, inflammatory patches with grayish white scales. It is symmetrically located on the elbows, knees and scalp. Psoriasis is a disease state that is affected by genetic, immunologic and environmental factors which cause abnormal proliferation, skin cell differentiation and inflammation.

The environmental factors include stress, depression, infections, sudden shock, alcohol, drugs, trauma and skin exposure. The epidermal keratinocytes multiply faster than in a normal skin migrating toward the epidermal surface in about 7 days as compared to normal cell turnover which is 21-28 days. These extra keratinocytes pile up over each other and create the thick patches that are characteristic of psoriasis.

When psoriasis appears on the scalp it is referred to as scalp psoriasis and can extend beyond the scalp and is often found behind the years and at the back of the neck. Due to the hair on the head and fact that the skin on the scalp is thicker, scalp psoriasis may require different treatments as compared to psoriasis on the rest of the body.

Hair Loss

Hair loss is simply described as thinning of hair or loss of hair on the scalp as well as other parts of the body. The medical term for hair loss is alopecia. Hair loss or alopecia can be categorized by scarring or non-scarring with non-scarring being more prevalent. Non-scarring alopecia can be either diffused or circumscribed with diffused being more prevalent. Diffused hair loss can be either chronic or acute with a more equal distribution between chronic and acute.

Nonscarring Alopecia: Hair loss without permanent destruction of the hair follicle.

Scarring Alopecia: A less common form of hair loss with a permanent destruction of the hair follicle which is replaced with scar tissue.

Diffused Alopecia: This is a condition that involves a decrease in hair density all over the scalp.

Circumscribed Alopecia: Loss of hair in a targeted area, often presenting with a patchy appearance.

Chronic Alopecia: Hair loss lasting for greater than six months. It can be permanent and progressive.

Acute Alopecia: Hair loss that lasts less than six months and is typically triggered by a lifestyle disruption, change or trauma.

Chronic Hair Loss

Chronic hair loss is classified by hair loss that presents for a period of time greater than six months. Androgenetic alopecia (AGA) is a genetic condition and one of the most common types of chonic hair loss seen by Dermatologists worldwide. Affecting both men and women, androgenetic alopecia involves the gradual transition of thick, pigmented terminal hairs into thinner, shorter, wispy, nonpigmented vellus hairs. Hormone imbalances cause the growth phase (anagen phase) of the hair cycle to shorten causing the hair bulb to become smaller which gradual leads to finer hair and eventually local hair loss.

There are four factors that need to considered with understanding and treating chronic hair loss. These include the:

• Inflammation Factor
• Vascular Factor
• Nutritional Factor
• Hormonal Factor

Inflammation Factor of Chronic Hair Loss

In women’s hair loss, inflammation negatively affects Substance P in the NK1 receptor, triggering the hair to prematurely progress from the Anagen to Catagen phase. Substance P is known to stimulate mitosis (cell division) in human keratinocytes. By extension, deficiency of Substance P negatively impacts hair growth.

In men’s hair loss, inflammation affects WNT. A significant regulating molecule within the hair follicle, WNT is critical in initiating hair follicle development. Thus, the WNT signaling molecule helps maintain the hair’s growth phase (anagen phase) and extends hair life by reconstructing the follicle and preventing hair miniaturization.

Vascular Factor of Chronic Hair Loss

In both men and women’s hair growth, vascular endothelial growth factor (VEGF) is essential to stimulating the creation of new blood vessels and vascular permeability. When VEGF synthesis is reduced, there is a negative affect on blood flow to the hair bulb, thus oxygen and nutrient delivery is decreased which does not allow for proper hair growth.

Nutritional Factor of Chronic Hair Loss

In both men and women’s hair growth, poor quality food choices lack nutritional value and lead to poor nutrient delivery to the hair bulb.

Hormonal Factor of Chronic Hair Loss

Androgens are male sex hormones and testosterone is the male hormone most people are familiar with. Dihydrotestosterone, also known as DHT, is another male androgen that is extremely strong and is considered extremely more potent than testosterone. Clinical studies have shown that DHT increases as men become bald and the number of the number of DHT receptors increases. A specific enzyme in the body, known as 5-alpha reductase, converts testosterone into DHT. The DHT then attaches to the receptors on the hair follicle which causes the hair to miniaturize, leading to balding. Blocking testosterone from converting to DHT is a clinically proven method of delaying the progression of chronic hair loss in men.

Chronic Hair Loss in Men

Fifty percent (50%) of men over the age of fifty will be affected by androgenetic alopecia which is more commonly referred to as male-pattern baldness. The hair typically recedes in a well defined and familiar pattern that takes the of the letter “M”. Beginning at the temples, the hair continue to thin on the top of the head (crown) and progress to partial or complete baldness.

A variety of medical conditions have been associated with this type of male hair loss. These include:

• High blood pressure (hypertension)
• Prostate issues (enlarged prostate, prostate cancer)
• Insulin resistance (obesity, diabetes)

Chronic Hair Loss in Women

Androgenetic alopecia in women, or female-pattern baldness, more typically begins in the 40s or with the onset of menopause. The hair loss pattern is very different as compared to men, with women experiencing general thinning all over the scalp without a receding hairline. Females rarely experience compete baldness.

Female androgenetic alopecia has been associated with a greater risk of hormonal imbalance and polycystic ovary syndrome (PCOS) which can lead to:

• Weight gain
• Irregular periods (menstruation)
• Acne
• Excess facial hair (hirsutism)

Acute hair loss

Acute hair loss is associated with hair loss that comes on suddenly and lasts less than six months. The medical term is telogen effluvium (TE) and it is thought to be the second most common form of hair loss dermatologists see. Telogen effluvium happens when there is a change in the number of hair follicles growing hair. The anagen (growth) phase slows down which mean less hair moves into the catagen (transition) and telogen (resting) phases. The percentage of hair in the telogen (resting) phase increases from the normal 5-10 percent to as much as 30 percent, meaning there is increased shedding.

The most outward sign of telogen effluvium is often excess hair seen in the hair brush/comb or in the skin or shower drain. There is usually no hair line recession. The thinning is diffused and may be more prevalent on the top of scalp versus sides or back. It is also very common that is the secondary result to an event or pathology which occurred as much as 2-4 months earlier. Regardless of cause or extent, telogen effluvium is not permanent. It can be reversed since the hair follicles are not irreversibly damaged or affected.

There are four factors that need to considered when understanding and treating chronic hair loss. These include the:

• Anagen Entry Factor
• Anagen Termination Factor
• Vascular Factor
• Nutritional Factor

Anagen Entry Factor of Acute Hair Loss

The NOGGIN Signal is a protein produced by the dermal papilla and is essential for hair follicle development. When it reaches a certain concentration, it triggers the hair to move from the telogen phase to a new growth phase (anagen phase). Activation of the NOGGIN signal protein can be involved in a faster or slower re-entry into the growth phase and is thought to influence short term hair loss.

Anagen Termination Factor of Acute Hair Loss

Tumor Necrosis Factor (TNFα) are pro-inflammatory cytokines that are involved in cell proliferation, differentiation and cell death. These cytokines play a part in regulating the transition from the anagen phase (growth phase) to the catagen phase (transition phase). If there is an increased level of TNFα it can result in shortening of the normal anagen phase which will lead to hair loss. In patient with telogen effluvium, increased levels of this molecule have been identified

Vascular Factor of Acute Hair Loss

Just like with chronic hair loss, vascular endothelial growth factor (VEGF) is essential to stimulating the creation of new blood vessels and vascular permeability. There is a possible decrease in VEGF in stressed induced telogen effluvium.

Nutritional Factor of Acute Hair Loss

Foods that don’t provide sufficient nutritional value may also lead to acute loss in very much the same way it can affect chronic hair loss.

There are a variety of health related and lifestyle related reasons that can cause acute hair loss or telogen effluvium. Each can literally cause a shock to the hair follicle that causes it to shut down for a while. In some cases there can be a great deal of shedding and it often occurs week or months after the initial cause has passed. One the health concern has passed or lifestyle cause has been discontinued the telogen effluvium subsides and the hair regrows.

Health Related Causes

• Postpartum Hair Loss, also called postpartum alopecia: This is the classic short term telogen effluvium caused by the sudden changes in hormone levels at birth.
• Post-Surgical Shock
• The affect of various medications/vaccinations particularly antidepressants
• Physical trauma or injury
• Bariatric Surgery

Lifestyle Related Causes

• Crash dieting
• Seasonal hair loss
• Poor dietary habits
• Fatigue
• Stress