Summary about Disease
Phytophotodermatitis is a skin reaction that occurs when the skin comes into contact with certain plants containing photosensitizing chemicals (furocoumarins, also known as psoralens) and is then exposed to ultraviolet (UV) light, usually from the sun. It's essentially a chemical burn caused by the combination of plant chemicals and sunlight. The reaction results in inflammation, blistering, and subsequent hyperpigmentation (darkening) of the skin in the areas affected.
Symptoms
Redness and inflammation of the skin
Burning or itching sensation
Blisters (small or large) that may weep or crust
Hyperpigmentation (darkening of the skin) after the initial inflammation subsides. This can last for weeks or months.
The rash often appears in streaks or patterns corresponding to where the plant touched the skin.
Pain can be present, especially if blisters are large.
Causes
The primary cause is contact with plants containing furocoumarins (psoralens) followed by exposure to UV light (sunlight or tanning beds). Common plants responsible include:
Limes (especially lime juice)
Lemons
Celery
Parsley
Wild parsnip
Giant hogweed
Dill
Fig
Carrot greens
Rue The psoralens absorb UV light and become activated, damaging skin cells.
Medicine Used
Treatment focuses on alleviating symptoms and preventing secondary infection. Common medications include:
Topical corticosteroids: To reduce inflammation and itching (e.g., hydrocortisone, triamcinolone). Stronger corticosteroids might be needed for more severe reactions.
Oral antihistamines: To relieve itching (e.g., diphenhydramine, cetirizine).
Pain relievers: Over-the-counter pain relievers like ibuprofen or acetaminophen can help with pain.
Cool compresses: To soothe the affected area.
Antibiotic ointments or oral antibiotics: If secondary bacterial infection develops.
In severe cases: Oral corticosteroids may be prescribed by a doctor.
Is Communicable
No, phytophotodermatitis is not communicable. It is a reaction to a plant substance and sunlight, not an infectious disease. It cannot be spread from person to person.
Precautions
Identify and avoid: Learn to identify plants known to cause phytophotodermatitis in your area and avoid contact with them.
Protective clothing: Wear long sleeves, pants, gloves, and other protective clothing when handling potentially problematic plants.
Wash thoroughly: If you come into contact with a potentially problematic plant, wash the exposed area immediately with soap and water.
Sunscreen: Apply broad-spectrum sunscreen (SPF 30 or higher) to exposed skin, especially after potential plant contact.
Be careful with food and drinks: Be mindful of lime or lemon juice splashing on your skin when preparing drinks or meals outdoors.
Gardening awareness: Gardeners should be particularly cautious when handling plants.
How long does an outbreak last?
The duration of an outbreak can vary depending on the severity of the reaction and individual factors.
Initial inflammation and blistering: Typically lasts for a few days to a week or two.
Hyperpigmentation (darkening of the skin): Can last for weeks to months. In some cases, it may persist for a year or longer. The hyperpigmentation will eventually fade over time.
How is it diagnosed?
Diagnosis is usually made based on:
Medical history: The doctor will ask about potential exposure to plants and sunlight.
Physical examination: The characteristic appearance and pattern of the rash are often diagnostic. The doctor will look for redness, blisters, and streaks in areas exposed to sunlight.
Patient report: Knowing if the patient was in contact with certain plants, like limes when making drinks, will help.
Sometimes: A skin biopsy may be performed in rare cases to rule out other conditions.
Timeline of Symptoms
Initial Contact & Exposure: Contact with the plant and then exposure to sunlight.
24-48 Hours: Redness and itching begin to develop.
48-72 Hours: Blisters may form. Burning sensation increases.
3-7 Days: Blisters may weep or crust over.
1-2 Weeks: Initial inflammation subsides.
Weeks to Months: Hyperpigmentation (darkening of the skin) develops and gradually fades over time.
Important Considerations
Severity varies: The severity of the reaction depends on the amount of plant exposure, the concentration of psoralens, and the intensity of UV light exposure.
Photosensitivity: Some individuals are more sensitive to psoralens than others.
Secondary infection: Blisters can become infected. Seek medical attention if you notice signs of infection (increased pain, redness, swelling, pus).
Hyperpigmentation: While the darkening of the skin is usually temporary, it can be cosmetically bothersome. Sun protection is crucial to minimize hyperpigmentation.
Giant Hogweed: This plant is particularly dangerous. If you come into contact with Giant Hogweed, seek immediate medical attention.
Lime Juice: A common cause is from lime juice on the skin while outdoors, often when making drinks. Be careful when handling limes outside.