SYMPTOM
Crusting on nose and ears
Owners may observe crusting on nose and ears in their pet, which can present in various ways depending on the underlying cause.
Dermatological
Crusting on the nose and ears can reflect primary skin conditions such as pemphigus foliaceus or other autoimmune skin disorders, where the body's immune system targets components of the skin surface. Dermatophytosis (ringworm, a fungal infection) may also produce hair loss, scaling and crusting, including on the face.
Environmental and allergic
Contact reactions or photosensitivity may produce crusting on thinly haired or exposed skin, particularly the ear tips and nasal bridge. In some cases, chronic rubbing or scratching driven by underlying allergic disease can lead to secondary crusting and erosion of these areas.
Infectious
Bacterial overgrowth or secondary infection following trauma or another primary process can lead to crusting, often accompanied by moisture or odour. Certain parasitic conditions, such as sarcoptic mange, may produce crusting on the ear margins and face in their early stages.
Immune-mediated
In dogs, discoid lupus erythematosus, an autoimmune skin condition, mainly affects the nasal planum, causing loss of pigment, scaling, erosions and crusting. The ear flaps are involved less often. It is very rare in cats.
Nutritional or metabolic
Deficiencies in certain trace elements, such as zinc, can manifest as crusting around the face and pressure points, particularly in some breeds. Metabolic disturbances affecting skin barrier function may also contribute to crusting in exposed areas over time.
Neoplastic
Certain tumours, including squamous cell carcinoma, may present as non-healing crusted lesions on sun-exposed areas such as the nasal planum and ear tips. This is seen mainly in cats with pale or unpigmented skin, and is rare in dogs. These changes tend to be progressive and may involve ulceration beneath the crust.
Why timing matters
Early observation
When crusting first appears, it often reflects a relatively recent change in the skin's barrier or immune environment. Early crusting may follow a discrete event, such as exposure to an irritant, a minor injury, or the onset of an infectious or allergic process. The distribution at this stage can offer clues: bilateral symmetry may point towards systemic or immune-mediated patterns, whilst asymmetry may suggest localised trauma or infection.
Later presentation
Crusting that persists or recurs over weeks to months can indicate either a chronic underlying process or incomplete resolution of an initial trigger. The skin in affected areas may become thickened, pigmented, or scarred, and secondary changes such as bacterial colonisation can complicate the picture. Recurrent crusting in the same location may suggest ongoing exposure, a relapsing immune process, or a structural change in the skin itself.
Some patterns of crusting remain stable or wax and wane with environmental factors, whilst others progress steadily. The texture, colour, and adherence of the crust can shift over time, as can the presence of associated signs such as redness, swelling, or hair loss. Individual variation in healing capacity, immune responsiveness, and environmental exposure means that two animals with similar initial crusting may follow quite different trajectories.
Conditions commonly associated
Pemphigus
The face and ear flaps are commonly affected in pemphigus foliaceus, developing thick yellowish crusts.
Discoid Lupus Erythematosus
Discoid lupus erythematosus causes loss of pigment, erosions and crusting, and in dogs the nasal planum is the most commonly affected site, where the normal cobblestone surface is lost. Lesions spread to the skin around the eyes and lips or to the ear flaps less often, and ultraviolet light appears to worsen the condition.
Squamous Cell Carcinoma in Cats
Squamous cell carcinoma in cats frequently develops on the ear tips and nose, particularly in white-coated individuals, where chronic sun damage progresses to invasive cancer. Crusting in these areas may reflect the surface changes that accompany abnormal cell growth and tissue breakdown.
Sebaceous Adenitis
Sebaceous adenitis may cause crusting on the ears and face when inflammation destroys the sebaceous glands, disrupting the normal oil production that keeps skin supple. The loss of these glands can lead to scaling, crusting, and changes in coat quality, particularly in predisposed breeds.
Atopic Dermatitis in Dogs
Atopic dermatitis in dogs can lead to crusting on the ears and face when chronic inflammation and self-trauma from itching disrupt the skin barrier. Secondary bacterial or yeast infections often develop in these areas, contributing to crust formation and further skin changes.
Squamous Cell Carcinoma of the Nasal Planum
In cats, sun-damaged, poorly pigmented skin on the nose affected by this cancer often starts as a crusted, reddened area that owners initially mistake for a scab. This tumour is rare in dogs.
Mosquito Bite Hypersensitivity in Cats
In cats, repeated mosquito bites on thinly haired areas like the nose and ear margins can trigger an allergic reaction that leaves crusted, scabbed skin in these spots.
Vasculitis
Cutaneous vasculitis is uncommon. Its lesions include purple discolouration, reddening, well-demarcated ulcers, crusts and sloughing of dead tissue, typically on the ear flaps, tail and footpads, and crusting with tissue loss along the ear margins can be one sign.
When to explore further
If the crusting persists beyond a few weeks despite no obvious ongoing irritant or injury, or if it recurs in a cyclical pattern.
If the affected areas begin to ulcerate, bleed, or show progressive tissue loss rather than healing.
If crusting is accompanied by other signs such as lethargy, appetite change, lameness, or crusting elsewhere on the body.
If the distribution is symmetrical and involves multiple sites, particularly the face, ears, and footpads.
If the animal is experiencing discomfort, such as scratching, head shaking, or avoiding touch to the affected areas.
Crusting on the nose and ears gains meaning in the context of the whole animal: its breed, age and environment, and any other changes that may have occurred alongside. Observing whether the crusting is stable, spreading, or shifting in character can be useful information. These observations, together with the animal's history and broader health picture, can help frame conversations about what may be contributing and what options for exploration might be available.
Last reviewed: 9 October 2026 · Dr Alastair Greenway MRCVS