A sunscreen with a sun protection factor (SPF) of 15 blocks approximately 93% of UVB radiation and a sunscreen with SPF 30 blocks approximately 97% of UVB radiation. Most chemical sunscreens (e.g. benzophenone) block 95% of UVB rays, but not UVA rays. The ideal sunscreen is a physical sunscreen (e.g. titanium dioxide that reflects rays) combined with a chemical sunscreen. Following treatments with lasers and IPL using high fluences, blisters or small erosions and ulcerations may occur. It is necessary first of all to avoid a secondary infection that may cause a scar. If topical antistaphylococcal penicillin (e.g. fucidic acid) is used under occlusion, there is a high risk of developing resistance towards this penicillin. Instead, after cleansing, hydrogen peroxide may be used twice daily. For an ulcerating haemangioma, a hydrocolloid (e.g. Mepilex) that not only absorbs fluid but also diminishes pain can be used. For a capillary malformation with no ulceration and only slight purpura or erythema, a moisturiser applied daily may suffice. A group IV steroid applied locally can prevent scarring. Patients should always be encouraged to come back as soon as there is any problem with healing, and a quality foundation to cover the purpura or the lesion should be recommended.