SYMPTOM
Crusty lesions on ear tips
Owners may notice scabs or crusts along the edges or tips of the ear flaps, sometimes with redness, scaling, hair loss, scratching or small sores that bleed.
Solar Dermatitis and Squamous Cell Carcinoma
Chronic ultraviolet exposure to the thinly furred ear pinnae produces a predictable progression from pink, scaly skin to crusting and eventual ulceration at the tip margins. White cats and those with white or pale ears are disproportionately affected, since they lack the protective pigment of darker-eared cats: white cats have about 13 times the risk of skin squamous cell carcinoma of cats of other coat colours. This sun damage can turn into squamous cell carcinoma, a skin cancer, and crusts, ulcers or bleeding that do not heal cannot be told apart from early cancer without a biopsy.
Ectoparasitic Infestation
Notoedric mange mites cause dry crusting that first appears on the edge of the ear flap nearest the head, spreading from there across the ear, face, eyelids and neck if left untreated. This mite is rare in Europe but spreads quickly between cats in contact. Ear mites more typically cause debris and inflammation within the ear canal itself, with any crusting appearing at the base of the ear from self-trauma rather than at the tips. Both cause intense itching, and kittens or cats from multi-cat or shelter environments are more frequently affected.
Autoimmune Skin Disease
Pemphigus foliaceus produces crusting on the ear flaps, usually on both sides, often alongside similar lesions on the face and in the skin folds around the claws, as the immune system disrupts the normal adhesion between skin cells. Many affected cats are itchy, and more than half of cats with active disease also show lethargy, fever or poor appetite. The lesions can look similar to infectious crusting, and they persist despite standard antimicrobial treatment.
Insect Bite Hypersensitivity
Mosquito bite hypersensitivity produces crusted, sometimes swollen lesions on the exposed ear tips, often with similar lesions on the bridge of the nose and the footpads, following a seasonal pattern that tracks mosquito activity in the warmer months. It is uncommon, and most reports come from warmer climates. Outdoor cats are more exposed, indoor-only cats are rarely affected, and lesions often improve markedly once the cat is kept indoors.
Cold-Induced Skin Injury
The ear tips have a relatively poor blood supply and minimal fur or fat for insulation, making them vulnerable to frostbite during prolonged exposure to temperatures below freezing. Affected skin first looks pale, grey or bluish, then red and sore as it thaws, and signs can take several days to appear. Badly damaged tips turn dark blue to black and slough off over days to weeks. Ear tip damage like this can have other causes, and the cause cannot be judged from the appearance at home.
Why timing matters
Early observation
Sun damage found before it turns into cancer can be managed with local treatments, and squamous cell carcinoma that is still confined to the ear tip can usually be removed by taking off the affected part of the ear, with a good published outcome.
Later presentation
On a white or pale ear tip, a crust that keeps coming back, does not heal, ulcerates or bleeds raises the possibility that sun damage has already turned into skin cancer.
Intense itching, or spread to the face and to other cats in the household, points more towards mites; crusts on the face and around the claws, with lethargy or fever, point more towards pemphigus foliaceus.
Conditions commonly associated
Squamous Cell Carcinoma in Cats
Squamous cell carcinoma in cats often develops on the ear tips of white-coated individuals following chronic sun damage, with redness and scaling first, then crusts, scabs that do not heal and ulcers as the precancerous change turns into invasive cancer.
Pemphigus
Pemphigus foliaceus often affects the ear flaps in cats, where autoimmune attack on the connections between skin cells leads to crusting and scaling. In a review of published feline cases the ear flaps were affected in 78% of cats and the skin around the claws in 52%.
Squamous Cell Carcinoma of the Nasal Planum
The same sun-related skin damage that produces this nasal cancer can affect the ear tips as well. Around 30% of cats with skin squamous cell carcinoma have lesions at more than one site.
Squamous Cell Carcinoma of the Pinna in Cats
Persistent crusting along the rim of the ear is a common early presentation of squamous cell carcinoma of the pinna, where sun-damaged cells thicken and ulcerate.
Mosquito Bite Hypersensitivity in Cats
The thinly haired ear tips are one of the sites mosquitoes bite, alongside the bridge of the nose and the footpads, and hypersensitivity to the bites produces raised, crusty lesions there.
When to explore further
When the symptom is persistent or worsening
When other signs are present alongside
When daily activities or quality of life are affected
When there is uncertainty about the cause
When a crust on a white or pale ear tip ulcerates, bleeds or keeps returning
Noting when this symptom occurs, any triggers, and how it changes over time can provide useful information for veterinary discussions.
Last reviewed: 9 October 2026 · Dr Alastair Greenway MRCVS