Hierarchy of effective sun protection

1.    Avoid the sun
2.    Cover with a physical barrier
3.    Topical sunscreen

1.    Avoid the sun

UV Index at your time and place
Get in the habit of watching the UV rating along with other weather factors. You can track it on your phone via websites, apps, or widgets. Certain times of day and certain places are higher. If you must be outside during high UVI times,  be extra careful.
 Personal sun tolerance
Conditions like ichthyosis and many other factors impact your personal tolerance and indicate a need for a more conservative approach.

2.    Cover with a physical barrier

Why Physical Rules
•    Clothing, gloves, and sun blankets offer more reliable coverage and no re-application.
•    UPF rated fabrics offer both UVA and UVB protection. Both of these factors contribute to skin cancer. With sunscreens, especially in the US, UVA protection is prioritized and the UVB protection is variable.
 
UPF fabrics are tested—usually 50+
Keep in mind normal textiles are not tested and therefore vary. An average t-shirt has a UPF of 5-7 when dry, UPF 3 wet. If you are unsure of an item…keep in mind, if you can see through a fabric, so can the sun.

3.    Topical sunscreen

Apply enough
•    For face: 2-4 fingers’ worth, or 1/4 ts. Include neck, eyelids, and ears. If thinner sunscreen, 3 fingers’ worth.
 
•    For body: 2 tb
•    Do not mix SPF with other lotions or makeup
 
Apply often
•    For people with sensitive skin, re-applying every hour is recommended. A minimum of every two hours is the universal recommendation.
•    Consider factors of swimming, sweating, and rubbing when you time your reapplication.

The Best Sunscreen is ...

The one you will use. Cost, feel, and wear will impact how likely you are to adequately use your sunscreen. Look for one you like and the benefits of regular, adequate use are likely to outweigh the potential drawbacks. If you want to go deep into the research, here is a great resource.
 From EWG.org

But still…Mineral vs Chemical?

People with ichthyosis have a malfunctioning skin barrier. Everything we apply, we absorb--to a much greater degree than unaffected skin. The most toxic chemicals to avoid are Oxybenzone and Octinoxate.  Mineral sunscreens usually skip the most problematic chemicals in favor of zinc and/or titanium dioxide. The downside to mineral sunscreen is often user experience—they can be thick, white, chalky, and cakey. You can search for any particular sunscreen and get safety scores here.

What are the risks for each active ingredient?

From ReefRepair.com, citing EWG SKinDeep ratings

So do I need to look like a ghost?

“Clean chemical” sunscreens avoid the worst offenders and are much less likely to leave a white cast. Avobenzone is considered “clean chemical”—if you want chemical, look for this active.

SPF

Look for sunscreens that are SPF 15 – SPF 50. Anything higher than 50 is unlikely to offer benefits and could have greater health risks.

Watch Expiration Dates

The active ingredients in ALL sunscreens degrade over time and render them useless. Degradation of your sunscreen begins once it’s compounded, then accelerates when you open it, and speeds up more if it’s stored in heat and light. When you buy your sunscreen, make sure the expiration is clear, and consider using permanent marker for reminders of when to toss, especially if you have several identical items. Don’t store sunscreen in your car. Don’t use sunscreen that’s been open more than 12 months.

Sprays and powders just increase your risks

Sprays and  powders feature all the risks of creams and add another—inhalation. If absorption is the enemy, ingestion is a supervillain. Avoid aerosols and powders, due to safety concerns around inhaling nanoparticles of the active ingredients.

What about shade and clouds?

Getting out of direct sun is helpful for reducing (not eliminating) UV exposure and for temperature management. But keep in mind UV light is still reflecting all around you. Partially cloudy skies, for example, have been shown to increase UV-B rays 25%!

Other helpful things

• Sunglasses that are polarized have excellent anti-glare properties which will shield your eyes from direct sunlight and harmful reflections.
• Lip balm with mineral sunscreen is a good choice since anything on your mouth is likely to get a bit ingested.
• Sun umbrellas will be thicker than most rain umbrellas and designed to maximize UV blockage.

This information is provided as a service to patients and parents of patients who have ichthyosis.  It is not intended to supplement appropriate medical care, but instead to complement that care with guidance in practical issues facing patients and parents.  Neither FIRST, its Board of Directors, Medical & Scientific Advisory Board, Board of Medical Editors, nor Foundation staff and officials endorse any treatments or products reported here.  All issues pertaining to the care of patients with ichthyosis should be discussed with a dermatologist experienced in the treatment of their skin disorder.