Phototherapy

Treatment of certain skin diseases using ultra-violet light is called phototherapy. Two types of UV rays are used in phototherapy, namely UVB and UVA. Treatment with UVB does not require intake of any sensitizing chemicals whereas treatment with UVA requires intake or application of photosensitizing chemicals called psoralens. Treatment can be done either using sunlight or artificial chambers that emit either UVB or UVA rays. Sunlight is the cheapest source of UV light that is accessible to all. But the disadvantage of using sunlight is that the UV irradiance varies with the time of the day, season of the year and the place, in addition to cloud and pollution effects. However, treatment using sunlight is still possible in India as UV irradiance does not vary much through out the year in most parts of India, provided the irradiance at different time of the day is known [See Sunlight In India].

Chambers emitting specific wavelengths of UV light are available in well established dermatology clinics and teaching hospitals. These are expensive but effective in delivering the required dose accurately, in addition to providing privacy.

Waldmann UV Therapy unit
uv100_smallThe important parameters to be known before starting the treatment are the irradiance of the source (milliwatts or microwatts/cm2/sec for UVA and UVB respectively), the dose to be delivered (joules or millijoules/cm2 for UVA and UVB respectively) which in turn depends on the type of the skin and the duration of exposure to the source. The treatment is done 2-3 times per week. The number of treatments required depend on the underlying disease.

Conditions that are treated using phototherapy are:

  • Vitiligo (leukoderma)
  • Psoriasis
  • Atopic eczema
  • Pruritus etc.

Mechanism of action include:

  • Immunosuppression
  • Antiproliferative
  • Melanogenic

Certain precautions are to be taken:

  • Phototherapy using the artificial chamber is preferably done in the evenings, after 5 p.m.
  • When using sunlight as the source, eyes and other exposed parts of the body should be protected for the rest of the day.
  • Sun screens should be used over the untreated areas during treatment with either sunlight or artificial chambers.

Vitilogo Lesions Before and After Phototherapy

phototherapy

Simple Excision

Simple excision is used to remove a variety of dermal and epidermal benign lesions. Sometimes, certain suspicious lesions are excised for histopathological examination. Various methods of excision are:

  • Shave excision: For benign, pedunculated lesions
  • Punch excision: For well defined, spherical lesions
  • Fusiform excision: For irregularly shaped or large lesions

The procedure is done under local anesthesia with aseptic precautions. For better cosmetic results, the lesions should be excised along the skin creases. Suturing is done with appropriate suture materials that cause less tissue reaction. Lesions that can be removed by simple excision are:

  • Seborrheic keratosis
  • Benign melanocytic nevi
  • Cutaneous neurofibroma
  • Cysts – epidermoid, acne, sebaceous
  • Other benign tumors of the skin

Precautions:

  • Look for keloidal tendency

excision

Electro Surgery

Electrosurgery is among the most versatile tool used in clinical practice. This modality allows for the rapid and cost-effective treatment of myriad of lesions, both benign and malignant.

electroElectrosurgery is a procedure by which the tissue is removed or destroyed by electrical energy. This energy, usually in the form of high frequency alternating current, is converted to heat as a result of tissue resistance to its passage. The heat is generated in the tissues themselves and in marked contrast with electrocautery, the treatment electrode in electrosurgery remains cold throughout the procedure.

Pic: Electrosurgery Equipment

Many electrosurgical devices are presently available to practitioners and over the years have become increasingly sophisticated. With modern electrosurgery, several different electrical outputs, each with a particular waveform and use may be generated by a single apparatus.

Clinical application of the appropriate output can result in selective incision, excision, ablation or coagulation of tissues.

Procedures carried out using this equipment are:

  • Electrodessication – For small lesions
  • Electrofulguration – For larger lesions
  • Electrolysis – Hair removal
  • Electrocoagulation – To control bleeding
  • Electrosection – Cutting tissues

Clinical Applications: Wide range of clinical conditions can be treated by this procedure:

  • Skin Tags
  • Small tumors on the face
  • Angiomas
  • Telangiectasias
  • Warts – filiform and plane
  • Seborroeic keratosis
  • Syringoma etc.

For tiny lesions, local anesthesia is not required, however larger lesions may require local anesthesia.

Post treatment care includes washing with soap and water and then applying antibiotic ointment. The wound produced by electrosurgery heals by secondary intention and healing time depends on the size, depth and amount of tissue destruction.

Skin Lesions Before and After Electro Surgery

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Cryo Surgery

Cryo surgery literally means ‘cold handiwork’. It makes use of local freezing for the controlled destruction or removal of living, but abnormal tissue. Mechanisms by which cryo surgery causes destruction of unwanted tissue are:

  1. Intracellular and extracellular ice formation causing mechanical damage to cells.
  2. Osmotic changes within the cells due to ice crystal formation that causes cell injury
  3. Thermal shock due to fall in the temperature of living cells.
  4. Denaturation of lipid protein complexes within the cell membranes.
  5. Vascular changes leading to necrosis of the tissue.
  6. Immunomodulation

The various refrigerants that can be used are:

  1. Ice
  2. Salt and ice
  3. Carbon dioxide snow
  4. Nitrous oxide
  5. Liquid nitrogen
  6. Freon
  7. Helium

Of these, CO2 snow and liquid nitrogen are routinely used by dermatologists. The cryogen is delivered through specialised devices.

 cryocan

Cryogun and Cryocan for storage of liquid nitrogen

A wide spectrum of skin conditions can be treated with cryo surgery. The most common ones are warts and molluscum contagiosum (viral infection), seborrhoic keratosis (benign tumor), moles (melanocytic nevi), developmental anomalies like hemangioma and lymphangioma, cysts, nodular cystic acne, acne scars, keloids, lentigines, basal cell carcinoma etc.

If done correctly with suitable freezing time, cryo surgery is an efficient, effective, simple and minimally painful procedure. Post treatment care should be taken to prevent secondary infections, scarring and pigmentation. Post inflammatory hyperpigmentation will improve over a period of 3-6 months.

Skin Lesions Before and After Cryotherapy

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Collagen Induction

Collagen Induction Tretament, or comonly known as Dermaroller Treatment, is an office procedure done for indications like

  • Lax skin, striae
  • Wrinkling
  • Rhytides
  • Scarring (acne and chicken pox)
  • Pigmentary changes (with vitamin C)

Acne Scars Before and Dermaroller

dermaroller

Introduced in 1997, it has several advantages over the common procedures done for wrinkling and scarring like ablative lasers and deep chemical peels, such as

  • Epidermis remains intact
  • Less downtime
  • No risk of hypo or hyperpigmentation

In this procedure, skin is punctured with microneedles, thereby inducing trauma-mimic, that in turn leads to a cascade of healing process causing the production of new collagen, elastin, ground substance and new blood vessels.

Histologically, the collagen induction treatment is shown to cause

  • Compact stratum corneum
  • Increase in the thickness of epidermis
  • Increase in the collagen and elastin, arranged in normal lattice work

From http://www.dnsroller.com/Needling of the skin is carried out using an instrument called dermaroller. A standard dermaroller is a drum-shaped roller studded with presterilized 192 (or more) fine microneedles in eight rows, 0.5-2 mm in length and 0.1 mm in diameter.

Procedure: Under topical anaesthesia, the dermaroller is moved over the skin in a series of rhythmic strokes. Application of L-Ascorbic acid or Tretinoin immediately after the roller procedure helps in reducing the pigmentary changes and scarring.

For acne and acne scars, initial treatment with chemical peeling followed by Dermaroller gives excellent results. Chemical peeling reduces the acne and normalizes the skin cycle.

For aging skin, Dermaroller treatment followed by application of vitamin C gives excellent results.

Chemical Peeling

Skin is a constantly regenerating organ; everyday, cells divide at the basal layer of the epidermis and move upwards to the top-most layer of stratum corneum from where they are shed. As they move upwards, they undergo lot of changes and this process is called keratinization.

Chemical peeling is a procedure wherein the exfoliation is accelerated and organised by application of exfoliating agents to the skin. The use of exfoliating agents to peel the epidermis dates back to ancient Egypt. Sour milk baths (containing lactic acid) were used by ancient Egyptian women to soothe the skin. The main purpose of peeling is for rejuvenation and to erase the marks of photo-damage and ageing.

The chemical peel creates changes in the skin by three mechanisms:

  1. Stimulation of epidermal growth through removal of stratum corneum
  2. Destruction of the specific layers of the damaged skin and replacement with normal tissue.
  3. Induction of inflammatory reaction deeper in the tissue, leading to activation of mediators of inflammation, resulting in the production of new collagen and ground substance in the dermis.

The agent, usually a solution, removes varying amounts of epidermis and depending on the strength, affects the dermal collagen. Wound repair consists of epidermal regeneration by migration from surrounding structures and replacement of new dermal connective tissue resulting in rejuvenation of the skin. In addition to improving the texture of the skin, peeling is also useful in the treatment of acne, acne scars, pigmentation caused by acne and other conditions like lentigines, melasma etc.

The choice of the agent depends upon the depth of the peel required. Broadly, peeling is classified into:

  • Superficial – Stimulates epidermal growth; agents used are CO2 slush, liquid nitrogen spray, glycolic acid (30-50%), Trichloroacetic acid (TCA, 10%)
  • Medium – Glycolic acid (70%), TCA (20-30%), combination of TCA and CO2 snow
  • Deep – Phenol.

Superficial and medium depth peeling are most often used in our set-up. Superficial peels are usually used for rejuvenation, comedonal acne and epidermal pigmentation. Medium depth peeling is used for acne scars and fine wrinkling due to ageing.

Chemical Peeling: Pre and Post Treatment

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