Discoid or Cutaneous Lupus

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Discoid Lupus (Cutaneous Lupus)
Discoid lupus is an autoimmune skin disease that causes depigmentation, and ulceration and crusting of the lips, nose and nasal planum, with loss of the 'cobblestone' appearance. It also affects areas around the eyes and sometimes the ears, often causing hair loss in these areas. Although the dog is not systemically ill, this condition is very painful, especially if the dog 'knocks' its nose, and as always with severe pain, this can make the dog very depressed.

Treatments for Autoimmune Skin Disease
Unlike systemic autoimmune diseases, there are several treatment options for autoimmune skin disease, these include, topical ointments, steroids (prednisolone), cytotoxic drugs, azathioprine and Atopica (cyclosporine) and a combination of tetracycline or doxycycline and  niacinamide (Vitamin B3) and 'steroid sparing' supplements such as essential fatty acids and natural Vitamin E in therapeutic doses.  Other drug options, if your initial choice doesn't work, can include: Chlorambocil, Gold salts, Pentoxifiline and Retinoids.

It is always worth trying other treatment options before using immunosuppressive doses of steroids and azathioprine, and very expensive drugs such as Atopica, however some skin disease, such as those in the pemphigus group may need more aggressive treatment.

Tetracycline or Doxycycline
There is a group of five antibiotics that go under the heading of 'Tetracyclines'. Two of these, tetracycline and doxycycline are indicated for the treatment of immune mediated skin disease having anti-inflammatory and immunomodulating effects, and the ability to suppress antibody production. Either one can be used in combination with niacinamide (vitamin B3) for the treatment of immune mediated skin diseases.

Note: Tetracycline (and Oxytetracycline) should be used with caution in dogs with renal impairment as it is eliminated from the body via the glomerula filtration and a build up of the drug can occur if used for prolonged periods. If it is necessary to give a dog with renal impairment Tetracycline or Oxytetracycline the dose should be lower than recommended but a lower dose may not address the problem and also the treatment is likely to be for many months at least.  However, Doxycycline is excreted in the faeces and does not affect renal function and can be used in animals with renal insufficiency. (Plumb's Veterinary Drug Handbook)

Important:  Niacinamide is also known as nicotinamide but it must not be confused with, Nicotinic Acid, (Niacin). Although Niacin acts identically as a vitamin, it increases the blood flow and blood pressure, and should not be used.

It may take 1-3 months before any positive results are seen (although duration of treatment is much longer) but, in spite of this, it is a popular treatment of choice for AI skin disease, as it is usually well tolerated and it avoids the use of steroids and other stronger drugs.  Many dogs do very well on this treatment regime. When good clinical improvement is seen the drugs can be gradually reduced and the dogs weaned off medication over a period of months. 

Dose:  Tetracycline & Niacinamide
Dogs less than 10kg : 250mg each Tetracycline and niacinamide every 8 hours
Dogs more than 10kg : 500mg each Tetracycline and niacinamide every 8 hours

Note:  Food can significantly reduce (up to 50% or more) the amount of Tetracycline or Oxytetracycline absorbed.   Avoid giving oral tetracycline within 1-2 hours of feeding or giving milk or dairy products

Doxycycline (5mg/kg/24 hrs) can be prescribed instead of Tetracycline and may be more convenient as it is given only once a day and, unlike tetracycline, food and dairy products do not affect its absorption.
(Plumb's Veterinary Drug Handbook)

Steroids
Steroids are life saving and can work like a miracle drug at times but obviously unless you have no choice, as in a life threatening situation, it is always worth trying other treatment options before using high doses of steroids and other more potent and expensive drugs. If you and your vet choose steroids to treat your dog's AI skin disease you may see quicker results, because the effect of steroids on the immune system is rapid.  However, the usual side effects of steroids can be expected. 

Steroids suppress the immune system in order to stop the destruction. The dose of steroids has to be `immunosuppressive', anything less and the treatment will not work and remission will not be achieved.   Over a period of months the dose is gradually reduced.

Immunosuppressive doses of steroids:
Prednisolone 1-2mg/kg/12hrs – starting at the lowest dose and gradually reducing dose over a period of months.

This example is base on a dog receiving an induction dose of  prednisolone 1.0mg/kg/12hrs
Dose                     Duration (based on clinical effect)

1.0mg/kg/q12h                    10-28 days
0.75mg/kg/q12h                   10-28 days
0.5mg/kg/q12h                    10-28 days
0.25mg/kg/q12h                   10-28 days
0.25mg/kg/q24h                   10-28 days
0.25-0.5mg/kg EOD                at least 21 days
0.25-0.5 mg/kg every third day   at least 21 days   

(Clinical Immunology of the Dog and Cat by Michael J Day). 


Note:  Steroids can cause an excess of stomach acid so, as a precaution, giving something to protect the stomach, such as Antepsin and/or Ranitidine alongside steroid treatment, is prudent.  Dogs treated with steroids without a gastroprotectant may develop stomach ulcers and all the problems associated with this avoidable complication.

Essential fatty acids and natural Vitamin E also play an active role in the treatment of skin diseases and should be included in any treatment regime.

•   Essential Fatty Acids (EFA's) are given in therapeutic doses, regardless of which primary treatment regime is used.  High doses of EFA's also play an `active' role in the treatment of skin diseases and should be included in the treatment regime and in low maintenance doses after remission.

EFA's are known to be `steroid sparing' in high doses. This means that they may ultimately, lead to a lower dose of steroids being used and this is especially useful in dogs that have to remain on steroids.

Example Therapeutic Dose: Essential Fatty Acids
"Effect appears to be dose related and optimum doses and the most effective combinations of these oils have not yet been determined. Daily doses of:
•   Evening Primrose oil 172mg/kg/day
•   Fish oil @ 44mg/kg/day
have been used in dogs over a one year period without ill effects."
(Ref: The Veterinary Formulary by Yolande M Bishop)

•   EFA dose should start at a high level until a response is seen.  This can take up to 12 weeks. EFA's can cause loose stools. If this occurs, start on a lower dose and build up to highest dose over a couple of weeks. Avoid Evening Primrose Oil in dogs with epilepsy.  Branded veterinary products are available. Follow manufacturer's dosing recommendations.

•   Natural Vitamin E (400-800iu/12hrs) encourages new cell growth.
(Ref: Clinical Immunology of the Dog and Cat by Michael J Day).
 
•   Chinese herbs are also noted as being effective but the owner would have to go to a vet who practices in natural treatments.

Atopica (Cyclosporin/Ciclosporin)
A drug licensed only a few years ago for atopic dermatitis in the dog is Atopica (cyclosporin), an immune modulating antibiotic. Since being licensed it is becoming very widely used in veterinary treatments.  Atopica is effective for immune mediated skin disease, but it is a very expensive drug and the cost is often prohibitive. Administration of grapefruit juice two hours before cyclosporin, however, leads to a significant increase of its bioavailability and the dose, and consequently the cost, of cyclosporin can be significantly reduced. (Reference: Effect of Grapefruit Juice on the Pharmacokinetics of cyclosporin in dogs. Veterinary Record Feb 7, 2004). The most frequently observed undesirable effects are vomiting, mucoid or soft faeces and diarrhoea. They are mild and transient and generally do not require the cessation of the treatment. Other infrequent side effects include: anorexia, change of hair coat, red and swollen pinnae (external ear), muscle weakness or muscle cramps. These effects resolve spontaneously after treatment is stopped. This drug should not be given to dogs with hepatic or renal insufficiency and it is advised to check these functions before treatment starts.  Atopica will initially be given daily until a satisfactory clinical improvement is seen. This could take up to 4 weeks. Treatment should be stopped after 8 weeks if no improvement is seen.  Once the clinical signs of the disease are satisfactorily controlled, Atopica can then be given every other day, gradually extending to every 3-4 days if a maintenance dose is required. Atopica should not be given within two hours of food.  For further details see the reference to cyclosporine in treatments for inflammatory/systemic autoimmune disease.