Hypermelanosis are a group of disorders characterized by abnormally darker skin that results from increased melanin production from a normal number of melanocytes. Disorders characterized by a higher than normal population density of melanocytes in the skin are usually referred to as “hypermelanocytes”.
Hypermelanoses may result from increased melanin in the epidermis (epidermal hypermelanoses) or the presence of melanin in the dermis(dermal hypermelanoses). Possible mechanisms for increased epidermal melanin without an increase in the number of melanocytes include the following:
· Increased melanosome production and transfer to keratinocytes;
· Increased melanosome size; and
· Decreased keratinocyte turnover, resulting in overloading of the keratinocyte with melanosomes.
In dermal hypermelanoses, melanosomes are formed in the epidermis by epidermal melanocytes & are transferred to the dermis, where they are found mostly within macrophages(melanophages). This phenomenon is called “epidermal melanin incontinence”.
Hypermelanoses can have sometimes characteristics anatomical distribution pattern.
Thus, Hyperpigmentation in the skin can result from:
1) Increased production of the melanin pigment, or pigment incontinence,
2) Accumulation of a large number of melanocytes, or
3) Deposition of other ( non-melanin) pigments or substances in the skin.
CLINICAL PRESENTATION OF FACIAL HYPERMELANOSIS
Hyperpigmentation disorders can be inherited or acquired, resulting from alterations occuring at any level in the melanogenesis pathway.
In clinical practice, acquired hyperpigmentations including Melasma, Post inflammatory hyperpigmentation, Solar lentigines and dyschromias of photoaged skin, represent the most commonest disorders of pigmentation.
· Melasma (Chloasma)
· Post Inflammatory Hyperpigmentation
· Solar lentigines
· Phototoxic Dermatitis
· Erythema Dyschromicum Perstans
· Poikiloderma of Civatte
· Riehl’s melanosis
· Peribuccal Pigmentation of Brocq
· Drug induced facial hyperpigmentation
· Facial hypermelanosis secondary to systemic disorders
Exposure to sunlight, genetic predisposition, use of cosmetics and certain drugs are implicated in the pathogenesis of most facial hypermelanoses.
Diseases leading to hyperpigmentation in certain specific disease patterns do require attention & treatment.
The most effective treatment of hyperpigmentation is PREVENTION. Individuals from different ethnic backgrounds have different skin types. The protection against ultraviolet radiation cannot be overemphasized.
If hyperpigmentation occurs, a variety of treatment modalities are available.
The choice of proper treatment should take into account the type of melasma to be treated, the skin complexion of the patient, possible previous treatments, the expectations and compliance of the patient 7 the season iin which the treatment is started.
Cosmetic camouflage may help in certain case though it is a temporary solution.
Different treatment options available includes Pharmacological treatment, Chemical peeling & Physical treatment.
Critical points, such as patient selection, disease improvement and treatment safety evaluation should be considered to choose the best option for the patient.
Despite the choice of chemical peeling, lasers and other physical procedures, pharmacological management with hypopigmenting agents remains the cornerstone of the pigmentation therapy.
PIGMENTATION CONTROL TARGETS & EFFECTIVE AGENTS.
Pigmentation Control Target Effective Agents
Tyrosinase Inhibition Hydroquinone, resorcinols, kojic acid
Arbutin, ascorbic acid.
Tyrosinase copper chelation Ellagic acid
Inhibition of tyrosinase glycosylation Glucosamine
Melanosome transfer Niacinamide, protease inhibitors
Downregulation of tyrosinase Retinoids
Antioxidants Vitamin C compounds, Vit E
Antiinflammatory agents Hydrocortisone, phytosterol
Increased Epidermal turnover Retinoids, salicyclic acid
Both Physicians & Dermatologists are searching for long term solutions for hyperpigmentation problem.
The association of depigmenting agents with different mechanism of actions that act at different steps in pigmentation pathways is a useful strategy to improve clinical efficacy, reducing the duration of therapy and the risk of adverse events.
The combination approach should ideally be able to give faster results and increase patient compliance-----the key in pigmentation therapy.
DR CHETAN LALSETA
M.D.(SKIN & V.D.)
CONSULTANT DERMATOLOGIST &COSMETOLOGIST
MIRROR COSMETIC CENTRE,
INDIRA CIRCLE CHOWK,
CONTACT NO: 98251 99585