Calcinosis cutis–or why steroids may not be the best long-term solution.

Luna is a 8yr old English Bulldog who has been on Prednisone 20mg BID since 12/22/17. 5 weeks ago owners noticed black spots, they would rupture while the skin began to slough off.

Calcinosis cutis occurs when calcium crystals are abnormally deposited in the skin layers. Most lesions are asymptomatic, but some may be tender, painful, or oozing a whitish substance. Due to the stiffening of the skin, lesions may also restrict joint mobility or limit movement. In severe cases, vascular calcification can cause diminished pulses and cutaneous gangrene.

Predisposed dogs include pets receiving long-term steroids to control other diseases, such as chronic itching/allergies, inflammatory bowel disease, or autoimmune conditions. Additionally, dogs suffering from Cushing’s Disease can develop calcinosis cutis if their disease is not well controlled. 

Calcinosis cutis lesions commonly appear on the skin as bumps or flat raised areas (papules or plaques) with gritty yellow, white, or grey granules. The lesions are commonly surrounded by reddened skin, because calcinosis cutis often causes inflammation. The back, underarms and groin area are most commonly affected, but the lesions often start in one area and spread if the underlying cause is not controlled. Many animals with calcinosis cutis are itchy and uncomfortable. Their lesions often develop secondary infections, leading to red tinged or white-green discharge from the lesions and increased swelling and itching. 

Treatment - In the case of chronic steroid usage, the steroids will be decreased gradually and stopped after a suitable substitute medication is found.If the patient is found to have a secondary infection, this will be treated with the appropriate topical and oral antibiotics. Additional treatments can include non-steroidal medications to reduce itching, antimicrobial shampoos to decrease the risk of future infection, and/or oral minocycline and aluminum-based antacids to help bind calcium. When appropriate, a topical gel medication (Dimethylsulfoxide –DMSO) is added to encourage the reabsorption of calcium from the skin. Regular blood work monitoring is often recommended to make sure the liver and kidneys are unaffected by the underlying cause or the treatment for calcinosis cutis.

Prevention of this happening would be to make sure our patients on steroids come in for rechecks often so we can assess them, adjust medications if possible, and avoid high-dose chronic steroid use.