The skin has minute glands called sebaceous glands which open into the hair follicle. These glands secrete an oily substance called sebum, which empties into the skin surface through the hair follicle. During puberty, the male sex hormones which are normally present both in males and females are on the rise and they activate the sebaceous glands to increase in size, which in turn leads to increase in the secretion of sebum. Secondly, the cells are shed more rapidly and they stick together, plugging the opening of the hair follicle, resulting in 'white heads'. The pigment melanin in the white heads when exposed to air, forms black heads. Thirdly, bacteria especially the 'propionibacterium acne' in number and add to the formation of acne. When the follicle gets clogged, its wall ruptures. The sebum, bacteria and dead cells escape into the surrounding tissue and lead to formation of more severe form of acne in form of pustules, nodules, abscesses and cysts.

Aggravating factors :

• Hormonal imbalance
• Polycystic ovarian disease
• genetic predisposition.
• Stress
• Use of cosmetics such as creams, oil based moisturizers, oil based foundations, etc
• Application of heavy oil or gel on the scalp leads to pimples on the back and forehead.
• People who work in chemical or oil industries and come in contact with hydrocarbons, heavy oils, cutting oil, wax, grease and coal tar derivatives can develop acne.
• Hot and humid climate.
• Drugs such as oral contraceptives, steroids, isoniazid, lithium, phenytoin, iodides etc. can cause pimples.
• Squeezing or picking at a pre-existing lesion will lead to secondary infection and increased pigmentation.

1. Wash your face with an anti-bacterial face wash at least 2-3 times a day.
2. Increase the intake of citrus fruits such as oranges, grapes, lime and lemon and other food stuff which are high in vitamin C and zinc.
3. Drink plenty of water.
4. Do not pick or squeeze the pimples as this causes infection, pigmentation and scarring.
5. Avoid the use of oily cosmetics, cleansing milk and gels.
6. Do not apply excessive hair oil if you have acne over the forehead.
7.Avoid stress factors.
8. Be patient and give medicines some time to act. You may have to take antibiotics for 8 - 10 weeks.
9. You may require surgical intervention in the form of comedone extraction, cryoslush, cryo-peel with liquid nitrogen or superficial chemical peel. These are best performed by a dermatosurgeon.

Surgical methods:
Subcision
Punch elevation / excision & grafting
Dermabrasion
Co2 or erbium laser ablation

Non surgical methods:
Chemical peels
Microdermabrasion
Non ablative lasers
Fraxel
Fillers
Microneedling & radiofrequency

1. Alopecia areata - Bald patches appear on the scalp, eyebrows, moustache or the beard area. It is an autoimmune condition.
   Male pattern or Androgenic alopecia - seen in those who are genetically predisposed.
2. Stress induced alopecia - due to:
   • Emotional stress
   • Starvation
   • Crash diets
   • Malaria, Tuberculosis, Typhoid etc.
   • After surgery
   • In hepatic or renal failure
   • Iron and Zinc deficiency
3. Post pregnancy.
4. In patients with thyroid or pituitary disorder.
5. Patients with collagen vascular disease.
6. Drug induced - Patients on anti-cancer treatment, anti-thyroid drugs, cholesterol lowering agents and patients on anticoagulant therapy suffer from hair loss.

1. The hair sample must first be tested.
2. The cause if established should be treated.
3. If there is any bacterial or fungal infection, it must be treated.
4. Dandruff or lice if present, should be treated.
5. Alopecia areata can be treated intralesional injections of triamcenalone or hydrocortisone or both. More than one cycle may be required at the interval of 2 - 3 weeks. 'Phenolization', another technique to treat alopecia areata may also be done.
6. Patients with male pattern alopecia or diffused hair loss may apply 'minoxidil' after consulting a dermatologist. 'Finasteride' in low doses is also prescribed by dermatologists in male pattern alopecia.
7. Vitamin and Zinc supplements are essential for arresting hair loss and help hair regeneration.
8. Anemia if present needs prompt treatment with iron supplements.

Patients with male pattern alopecia can undergo hair transplantation. Hair transplantation may be of three types: 1) punch grafting 2) single hair transplant.3)The latest is: Follicle Unit Transplant.  The donor for the transplant is the patient himself. Therefore he should have adequate hair in the non-affected area from where the grafts can be taken.

Patients who are medically unfit for surgery, those who do not have adequate donor area or those who have scarring alopecia can go for non-surgical modalities of hair restoration. These may be in form of wigs, hair weaving hair clipping, hair bonding, falls, switches or demiwigs.

1. Use a good shampoo once or twice a week. Choice of shampoo depends on the hair type (normal, dry or oily).
2. A diet rich in proteins, iron and zinc should be consumed.
3. Drink 7 - 8 glasses of water everyday.
4. Psychological stress and anxiety lead to hair loss, so keeping them at bay is very important.
5. Physical trauma to the hair shaft caused due to vigorous combing, excessive shampooing, drying or brushing should be avoided.
6. Beware of trendy styles such hair bleaching and dying, they might cause more harm than good.
7. Avoid hair perming or straightening.
8. Use of rubber bands, buns and braids must be avoided.

The laser has a wavelength that specifically targets the pigment ‘melanin’ contained in the hair follicle & shaft. It penetrates the skin to the depth of 1.5mm which is where the hair bulb is located. Thus it works on the principle of selective ‘photothermolysis’. The laser pulses for a fraction of a second, penetrates the hair bulb without destroying the surrounding skin & vaporizes the pigment in the hair follicle. Thus the follicle is either destroyed or its re-growth is impeded. This is a non- invasive procedure & a large number of hair are targeted in a single flash of light.

During the treatment, patient may experience a mild stinging sensation described by most as  snapping of a rubber-band. However, most patients tolerate this.Also, a chill tip cooling hand piece is incorporated in the laser which protects the surrounding skin & reduces pain too. A local anaesthetic gel may be applied to those who are very sensitive to pain

Pityriasis alba : Hypo pigmented patch may be seen on the face usually in young children. It is common in winter and in those with history of atopy. It can be treated with a mild topical steroid.

Pityriasis versicolor : It is a superficial fungal infection caused by a yeast 'pityrosporum orbiculare'. Well defined hypo or hyper pigmented lesions with fine scales are found on the chest, back, neck and sometimes on the face. It is treated with topical and oral anti fungal drugs.

Leprosy : It is a chronic disease caused by 'mycobacterium leprae' and affects mainly the skin and nerves. A hypo pigmented patch with absent or decreased sensation is seen in tuberculoid type of leprosy (good immune response) whereas in lepromatous type (low immune response) the sensations may be normal. It can be cured with the help of drugs.

Vitiligo : This is an autoimmune diseases where de pigmented patches are seen, they may occur any where on the body. The treatment is detailed in the chapter on vitiligo.

secondary leucoderma : This occurs due to contact with certain chemicals phenol derivatives, glue of 'bindi', rubber slippers, plastic watch straps, photograph developing solutions or burns. It can be treated by spot dermabrasion or skin grafting.

Post inflammatory hypo pigmentation : It occurs after the healing phase of certain dermatoses such as eczemas, psoriasis, candidiasis etc.

Nevus depigmentosus : It is a congenital, well defined, hypo pigmented patch present since birth. It can be treated by spot dermabrasion or ablation with Co2 laser followed by ultra thin skin grafting.

Hyper pigmentation may either be due to increased melanin deposition in the epidermis or dermis. Epidermal pigmentary disorders respond well to treatment while dermal pigmentation may take a long time to lighten.

Melasma : Seen as brown patches on the face, it is more commonly seen in females. It occurs due to hormonal changes in the body. The pigmentation increases on sun sun exposure.

Peri-orbital melanosis : Also known as 'dark circles' may be heriditary, due to stress or eye strain

Freckles and Lentigenes : These are tiny black spots on the face and are genetic in origin.

Photomelanosis : This is increased pigmentation due to sun exposure. The pigmentation occurs on exposed skin, commonly on the face, neck and the back. The pigmentation may be patchy or as diffused darkening of the exposed skin.

Sun burn (tan) : A condition commonly encountered in fair skinned people due to excessive sun exposure.

Post inflammatory hyper pigmentation : It may be seen in the following cases Seen after healing has occured, like in acne, eczemas, contact dermatitis etc. Drug induced pigmentation. Pigmentation due to cosmetics especially those containing fragrance.

Macular lichen amyloidosis.

Nevus or 'Birth mark' : Usually seen at birth but may also appear at a later age.

Tattoo : Tattoos are pigments inserted into the skin for decorative purpose which may at times be a part of tradition. Usually these artificial pigments are inserted deep into the dermis which makes them permanent and stubborn

Melasma, Photomelanosis and post inflammatory hyper pigmentation can be treated with topical creams such as hydroxy quinine, tretinoin, topical steroids, alpha hydroxy acid creams, azelic acid, arbutin, liquorice, kojic acid. If the patient does not improve with these medicines other modalities should be used, which may be :

PUVA therapy enhances skin re-pigmentation. An oral psoralen compound is given to the patient. Two hours later , the de-pigmented patch on his body is exposed to ultraviolet-A (UVA) rays, for a fixed time duration. This should be supervised by a medical personnel. If UVA is not available then the patch is exposed to sun rays. The latter is known as PUVA SOL therapy.Treatment with UVB rays is another option. The most recent modality is treatment with Excimer

When the de-pigmented patch does not increase in size for a period of two years, it is said to be stable. This is the right time to perform vitiligo surgery.
If the patch is growing or is in an active phase, it needs treatment with medicines and / or PUVA till it stops growing.

Method to be used depends on the the type and site of lesion. Hence, selection of the appropriate surgical technique is important for good cosmetic results.
Miniature punch grafting.
Ultra thin skin grafting.
Suction blister grafting.
Therapeutic spot or regional dermabrasion.
Melanocyte culture and transplantation.
Tattooing

Multiple thin grafts of 2 - 2.5 mm diameter are taken from the donor site by special punches and grafted on to the diseased area. Once the grafts are 'taken up' the patient is advised to take PUVA or PUVA SOL. Re pigmentation occurs in 3 - 6 months and good cosmetic result is obtained.

A very thin skin graft (ultra thin) consisting of epidermis is grafted onto the dermabraded or laser ablated part of stable vitiligo. The graft falls off by 8 -10 days but there takes place a cellular uptake of melanocytes on to the abraded skin which gradually starts pigmenting, it takes 2 - 3 months for the pigmentation to merge and match with the surrounding skin color.

A prolonged suction (negative pressure) is applied to the donor site this raises a large bleb and a thin graft containing only the epidermis is obtained. This is grafted on to the dermabraded recipient surface. This technique is time consuming but gives good cosmetic results.

Melanocytes are cultured in artificial culture media. The de pigmented recipient site is dermabraded or laser ablated and the melanocyte suspension is applied to it. The area is covered with a collagen dressing and immobilized. Large areas can be covered with this method and excellent cosmetic results obtained.