Photobiomodulation reduces pain and inflammation, augments tissue repair and promotes regeneration of different tissues and nerves and prevents tissue damage in situations where it is likely to occur.
- Skin rejuvenation: skin starts showing its first signs of aging in the late 20s to early 30s and it usually presents with wrinkles, depigmentation, telangiectasia, and loss of elasticity. Common histologic and molecular-level features are reduction in the amount of collagen, fragmentation of collagen fibers, degeneration of elastic fibers, upregulation of matrix metalloproteinases, dilated and tortuous dermal vessels, and atrophy and disorientation of the epidermis. Photobiomodulation has been shown to be effective for improving wrinkles and skin laxity; increasing in production of pro-collagen, collagen, basic fibroblast growth factors, microcirculation, and vascular perfusion in the skin; decrease the process of programmed cell death.
- Acne: photobiomodulation decreases the androgenic hormones in the sebaceous gland, leads to bacterial destruction, affects the sebum secretion of sebaceous glands and change keratinocyte behavior, modulates cytokines from macrophages and other cells, which in turn reduce focal inflammation.
- Sun-protection: it is widely accepted that the UV range (< 400 nm) exposure is responsible for almost all damaging photo-induced effects on human skin. Some proposed mechanisms for UV induced skin damage are collagen breakdown, formation of free radicals, inhibition of DNA repair, and inhibition of the immune system. Photobiomodulation has protective effects against ultraviolet (UV)-induced skin damage mainly by triggering protective/repair responses to UV irradiation; generates a strong cellular defense against solar UV cytotoxicity in the absence of rising skin temperature [long-lasting (at least 24 hours) and cumulative phenomenon.]
- Herpes Virus Lesions: one of the most common virus infections is caused by herpes simplex virus (HSV). HSV is chronic and lasts one’s entire life. The exposure of the person to several kinds of physical or emotional stresses such as fever, exposure to UV light, and immune suppression causes virus reactivation and migration through sensory nerves to skin and mucosa, localizing particularly on the basal epithelium of the lips and the perioral area. Photobiomodulation has been suggested as an alternative to current medications for accelerated healing, reducing symptoms and influencing the length of the recurrence period. Even though mechanism of action is still not clear, an indirect effect of photobiomodulation on cellular and humoral components of the immune system involved in antiviral responses rather than a direct virus-inactivating effect was been proved in animal research.
- Vitiligo: Vitiligo is an acquired pigmentary disorder characterized by depigmentation of the skin and hair. The underlying mechanism of how the functional melanocytes disappear from the involved skin is still under investigation. However, findings suggest that regardless of the patho-genetic mechanism involved, keratinocytes, fibroblasts, melanoblasts and melanocytes may all be involved in both the depigmentation and also the re-pigmentation processes of vitiligo. Photobiomodulation stimulates epidermal and dermal cells inducing skin and follicular re-pigmentation.
- Hypertrophic Scars and Keloids: hypertrophic scars and keloids are benign skin tumors that usually form following surgery, trauma, or acne and are difficult to eradicate. Fibroblastic proliferation and excess collagen deposits are the 2 main characteristics and imbalance between rates of collagen biosynthesis and degradation superimposed on the individual’s genetic predisposition have been implicated in their pathogenesis. The use of photobiomodulation as a prophylactic method to alter the wound healing process to avoid or attenuate the formation of hypertrophic scars or keloids has been investigated. As result, significant improvements on the photobiomodulation treated vs the control scar were seen in all efficacy measures and moreover no significant treatment-related adverse effects were reported.
- Burns: photobiomodulation treatment decreases symptoms of burning, redness, swelling, and peeling, as well as facilitates faster healing.
- Psoriasis: Psoriasis is a chronic autoimmune skin disease. Psoriasis is characterized by the abnormally excessive and rapid growth of keratinocytes (instead of being replaced every 28–30 days as in normal skin, in psoriatic skin they are replaced every 3–5 days). This hyperproliferation is caused by an inflammatory cascade in the dermis involving dendritic cells, macrophages, and T cells secreting TNF-α, IL-1β, IL-6, IL-17, IL-22, and IL-36γ. Recently photobiomodulation has been considered for treatment of plaque psoriasis with a significant resolution of the plaques.