What are the other Names for this Condition? (Also known as/Synonyms)

• Chemical-Induced Phototoxic Reaction
• Drug-Induced Phototoxic Reaction
• Phototoxic Medication-Induced Photosensitivity

What is Phototoxic Drug (or Chemical) Induced Photosensitivity? (Definition/Background Information)

• Photosensitivity can be described as an allergic reaction of the body (or skin) on exposure to the sun. This immune reaction may also occur on the usage or consumption of certain drugs, medications, or chemicals, with subsequent exposure to sunlight (or ultraviolet light). This condition is termed as drug (or chemical) induced photosensitivity
• Drug (or chemical) induced photosensitivity can occur in the following manner:
  • Phototoxic Drug (or Chemical) Induced Photosensitivity, also known as Drug (or Chemical) Induced Phototoxic Reaction
  • Photoallergic Drug (or Chemical) Induced Photosensitivity, also known as Drug (or Chemical) Induced Photoallergic Reaction

Phototoxic Drug (or Chemical) Induced Photosensitivity occurs when there is a reaction between drugs (or chemicals) and ultraviolet (UV) light.

• Usually the individual is taking certain medications/drugs or using certain chemicals; but, when there is an exposure to UV light, the individual develops an adverse skin reaction
• The drugs/chemicals may be used for treatment or cosmetic purposes, or there may be an occupational exposure while working in agricultural fields or in an industrial plant. The chemical may also be commonly used in the kitchen or toilets, such as a cleaning fluid
• The signs and symptoms of Phototoxic Drug (or Chemical) Induced Photosensitivity can be local (confined to an area of skin) or systemic (widespread in the body). Thus, not only the skin, but other body parts and organs can also be affected. And, depending on the condition type it is classified as:
  • Topical Phototoxic Dermatitis: It is caused by cosmetics, therapeutic drugs, or industrial chemicals and the signs and symptoms are limited to the area of application/exposure
  • Systemic Phototoxic Dermatitis: It is caused by a photosensitizing drug/chemical and the condition affects several parts of the body or the entire body
• The primary treatment for Phototoxic Drug (or Chemical) Induced Photosensitivity is discontinuation or stoppage of the offending medication/drug/chemical. The prognosis of the condition is typically excellent with suitable treatment

Who gets Phototoxic Drug (or Chemical) Induced Photosensitivity? (Age and Sex Distribution)

• Phototoxic Drug (or Chemical) Induced Photosensitivity is an uncommon condition caused by a variety of chemicals/drugs/medications (that are administered for other underlying conditions or there is an unintentional exposure) with subsequent sun exposure. Any individual, of any age, may be at risk for the condition
• It can affect both males and females
• The condition occurs worldwide; individuals of all racial and ethnic background may be affected

What are the Risk Factors for Phototoxic Drug (or Chemical) Induced Photosensitivity? (Predisposing Factors)

• The key risk factor for Phototoxic Drug (or Chemical) Induced Photosensitivity is the administration of certain drugs or the contact with certain chemicals that can cause the condition as a side effect
• There a variety of medications, drugs, and chemicals observed to induce this condition

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Phototoxic Drug (or Chemical) Induced Photosensitivity? (Etiology)

Phototoxic Drug (or Chemical) Induced Photosensitivity occurs as an adverse reaction to certain medications or chemicals.

• The drugs/medications (including topical creams or lotions) are taken for various conditions. The exposure of the body to certain chemicals may also occur from an industrial or agricultural source. This is then followed by an exposure to ultraviolet light (either from the sun or from other sources)
• These drugs/chemicals cause the formation of free radicals, which when exposed to UV light causes the release of certain chemicals such as serotonin, prostaglandins, tumor necrosis factor alpha, and cytokines
• The offending drug/chemical potentially causes an abnormal cell-mediated immune response in the body, resulting in the associated signs and symptoms of the condition. However, sometimes, the appearance of signs and symptoms due to the drug or chemical may not be observed immediately

Phototoxic Drug (or Chemical) Induced Photosensitivity is classified as:

• Topical Phototoxic Dermatitis: The signs and symptoms occur at the area of drug/chemical exposure (where creams and lotions are applied or due to an unintentional chemical contact) and interaction with UV light or sunlight
• Systemic Phototoxic Dermatitis: The signs and symptoms are observed when an individual takes photosensitizing drug/chemical and there is a subsequent exposure to UV light

What are the Signs and Symptoms of Phototoxic Drug (or Chemical) Induced Photosensitivity?

The signs and symptoms of Phototoxic Drug (or Chemical) Induced Photosensitivity can be local or systemic.

• Local or topical condition: The signs and symptoms are mostly confined to the area of exposure
• Systemic condition: Not only the skin, but other parts of the body may also be affected

The condition may have a slow onset. In some cases, the appearance of the signs and symptoms is not immediately observed after commencement of the drug or on exposure to the chemical; it may take weeks and months for them to develop.

The signs and symptoms may include:

• Itching all over the body
• General body aches
• Fever
• Redness of skin
• Blister formation (vesicles and bullae)
• Hemorrhage can occur under the nails (subungual hemorrhage)

The severity of Drug (or Chemical) Induced Phototoxic Reaction may vary; it is difficult to predict who will get mild or severe symptoms.

How is Phototoxic Drug (or Chemical) Induced Photosensitivity Diagnosed?

The following are the diagnostic methods and tests that may be used for Phototoxic Drug (or Chemical) Induced Photosensitivity:

• A complete physical examination and a thorough medical and occupational history (which includes the use of any drugs, nature of occupation, etc.) are very important
• Dermoscopy: Dermoscopy is a diagnostic tool where a dermatologist examines the skin using a special magnified lens
• Skin or tissue biopsy: A skin or tissue biopsy is performed and sent to a laboratory for a pathological examination, who examines the biopsy under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis. A biopsy is performed to rule out other similar conditions

Note: In most cases, based on the signs and symptoms, a diagnosis can be made by the dermatologist through a physical examination and medical history study, without resorting to a biopsy.

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Phototoxic Drug (or Chemical) Induced Photosensitivity?

Complications of Phototoxic Drug (or Chemical) Induced Photosensitivity may include:

• Bacterial and fungal infections: The condition may cause continuous itching and scaling of the skin, which creates skin moistness, providing a suitable environment for bacteria and fungi to grow and thrive
• The skin heals with increased or decreased pigmentation
• The lesions can last for years resulting in self-image issues, emotional stress, and psychological trauma (depression) in some individuals

How is Phototoxic Drug (or Chemical) Induced Photosensitivity Treated?

The treatment of Phototoxic Drug (or Chemical) Induced Photosensitivity may include:

• Discontinuing the drug/medication (even topical ointment or cream) responsible for the side effect may result in a cure
• In case the condition is due to industrial or agriculture exposure to a certain chemical, then suitable protective measures may be taken to avoid coming into contact with the offending chemical
• Topical treatment includes cooling the skin using moist towels and moisturizing creams to soothe the condition
  • Use of topical ointments, lotions, and creams - these may be antiseptic and anti-inflammatory applications
  • Topical steroid creams can help reduce inflammation
• Systemic treatment may be required in some cases
  • It may include medications, such as aspirin and other non-steroidal anti-inflammatory over-the-counter painkillers
  • In severe cases, oral steroids and IV fluids may be necessary
• Providing reassurance and helping with feelings of stress and anxiety
• Follow-up care with regular screening and checkups are important, since the condition may last for many months and years

A few self-care tips and home remedies that may prevent aggravation of the condition may include:

• Completely avoid scratching the affected areas
• A comfortable, cool bath may help soothe the skin; but, avoid excessive washing and scrubbing of the skin
• Wear smooth cotton clothes
• Use only mild perfumes, soaps, and detergents
• Drinking lots of water or fluids

How can Phototoxic Drug (or Chemical) Induced Photosensitivity be Prevented?

Currently, it is not possible to prevent Phototoxic Drug (or Chemical) Induced Photosensitivity.

• Stopping the medication causing the condition as early as possible is important. The healthcare provider may prescribe alternative medications to treat the existing, underlying condition
• If the allergic reaction is following an exposure to industrial compounds or chemicals, then suitable protective or safety gear may be used to prevent any further contact with the chemical
• Periodic monitoring or follow-up of the condition with the healthcare provider is recommended

What is the Prognosis of Phototoxic Drug (or Chemical) Induced Photosensitivity? (Outcomes/Resolutions)

• The prognosis of Phototoxic Drug (or Chemical) Induced Photosensitivity is excellent with appropriate treatment
• In general, it is easier to treat topical or localized conditions than systemic or widespread conditions

Additional and Relevant Useful Information for Phototoxic Drug (or Chemical) Induced Photosensitivity:

Cleaning the skin too hard with strong chemicals or soaps may aggravate the skin condition. Care must be taken avoid strong soaps and chemicals that can potentially worsen the condition.