**4.1. Contraindication**

Nevertheless, many systematic reviews point that LLLT is an effective therapeutic modality on wound healing and diabetic foot ulcer recovery [20], but additional clinical studies must be performed in order to find out the best parameters of wavelength, dosage, and methodology

Do not use LLLT over any known malignant lesions unless: for pain relief during the terminal stages of the illness, and for cancer therapy side effects (e.g., oral mucositis, radiation derma‐

There is no evidence of harm to an unborn baby; however, there are no safety tests either, so for medico legal reasons it is recommended to not treat directly over the developing fetus.

Although relatively low intensity is far less likely to trigger any adverse events when treating

Photodynamic therapy (PDT) as a photochemistry process can kill cancer cells, inactivate infected pathogens, and demolish target tissue. In PDT process, one special material called photosensitizer or nontoxic dyes absorbs visible light and produces excited singlet state such as singlet oxygen and hydroxyl radicals that are able to attack to target cells [21]. Administra‐ tion of photosensitizer either topically or systemically in combination with irradiation appropriate wavelength laser is a promising treatment modality in wound healing especially for chronic pressure and decubitus wounds frequently encountered in diabetic and disable patients. The healing of chronic wounds and venous stasis ulcers of the leg is compromised by infection, yet PDT has an antimicrobial action [22]. Bacterial burden in chronic ulcer decreases by treatment with infrared radiation. A radiation via endogenous protoporphyrin (and/or protoporphyrin IX [PpIX] of bacteria) is virtually similar to a mild PDT [23]. It appears that PDT with suitable PS together with suitable laser parameters represents effective treat‐ ment modalities in promoting wound healing. PSs associates with three main groups of agents: azine dyes, macrocyclic dyes, and metallated derivatives [24–27]. An extensive range of PSs from different groups including azines, porphyrins, phthalocyanines, and chlorophyll

that region of the neck, we suggest not applying lasers directly over the thyroid.

**4. Photodynamic therapy and wound healing**

and especially appropriate treatment protocol.

364 Wound Healing - New insights into Ancient Challenges

**3.1. Relative contraindications**

*3.1.1. Cancer*

titis, etc.).

*3.1.2. Pregnancy*

*3.1.3. Thyroid*

**3. Relative contraindications/precautions**

Cutaneous hypersensitivity, porphyria, known allergies to porphyrins.

Both Aminolevulinic acid (ALA) and Methyl aminolevulinate (MAL) are in FDA pregnancy category C; reproduction studies have not been performed on animals.

Photodynamic therapy is not approved for use in children.
