Managing sebaceous adenitis and symmetrical lupoid onychodystrophy (Proceedings)

Sebaceous adenitis

• Etiology

• Unknown

• May be an immune mediated disease

• May be a genetically inherited defect – autosomal recessive trait.

• Keratinization abnormality with obstruction of sebaceous duct?

• Abnormality in sebaceous lipids?

• Clinical features ? 2 forms

• Sebaceous Adenitis with Hyperkeratosis – Long Coated Breeds

• Seen in all color variants of standard poodles (may be similar in other long?coated breeds of dogs such as Samoyeds and Akitas).

• A symmetrical partial alopecia and excess scaling with follicular casts.  Remaining hair is dull and brittle.

• Affects dorsal planum of the nose, top of head, dorsal neck and trunk, tail and pinnae.

• Non?pruritic and no offensive odor

• May develop secondary bacterial folliculitis with pruritus.

• Hair may become straight and lose its “curl”.

• Granulomatous Sebaceous Adenitis – Short Coated Breeds

• Affects short?coated breeds of dogs ? Vizslas, Weimaraners

• Begins as a moth?eaten alopecia with minimal to no scaling.

• Primarily affects the trunk, head and ears.

• Non?pruritic

• Diagnosis

• Histopathology

• Initial nodular granulomatous to pyogranulomatous inflammation at the level of the sebaceous glands.

• Depending on the type, there may or may not be prominent hyperkeratosis.

• Chronic cases develop a complete loss of sebaceous glands with fibrosis, atrophy of hair follicles and in some cases complete loss of the adnexa with fibrosis.

• Treatment

• Propylene glycol ? a hygroscopic lipid solvent that penetrates the horny layer and increases water content.  50?75% propylene glycol with water?applied daily as a spray.

• Bath Oil Treatments (light mineral oil) – 50:50 mixture of bath oil and water, spray over the entire body, rub into the hair coat well, allow to soak for 1-2 hours. Remove oil by bathing with dish soap 2-3 times, and then finish with a moisturizing shampoo and conditioner/crème rinse for the final bathing. Repeat q 7 days for the first month, the q 14-30 days prn.

• EFA Supplement - Derm Caps ES - 1 capsule BID; Evening Primrose Oil (EPO) - 500 mg BID.

• Anti?seborrheic shampoos, conditioners and emollients have been of little benefit.

• Treat secondary pyoderma if present.

• Isotretinoin (Accutane®) - 1 mg/kg SID-BID.

• Acetretin (Soriatane®) - 1 mg/kg SID-BID

• Cyclosporine (Neoral, Gengraf, Atopica) - 5 mg/kg BID.

• Vaseline Intensive Care Lotions daily without washing.

• Allerderm Spot-On – apply daily or from 1-3 times/week prn.

• Dermoscent Essential 6 – apply once weekly prn.

• Douxo Calm Shampoo and Spray – apply 3 times weekly.

• Douxo Seborrhea Shampoo and Micro-emulsion Spray – apply twice weekly.

• Essential fatty acid dietary supplement (Derm Caps ES) – 1 capsule BID + Evening primrose oil – 500 mg BID.

• High empirical dosages of purified fish oil daily (1000 mg?) – Marshall, Williams – Adv Vet Derm, Vol 1:446, 1990.

• Vitamin A – 8,000-10,000 I.U. – SID-BID x 3 months, then up to 20,000-30,000 I.U. – BID.  Needs to be esterified for stability and from a quality controlled and reliable manufacturer (DSM Nutritional Products – formerly Roche; Bio-Tech Pharmaceutical). Mark Papich – 600-800 I.U./kg SID.

• Tetracycline and Niacinamide – 10 mg/lb of each drug, not to exceed 500 mg TID of each drug.

• Doxycycline – 5-10 mg/kg SID, with or without concurrent Niacinamide.

• Prognosis

• Akitas – tends to be more severe, chronic recurrent pyoderma more  of a problem, possible signs of systemic illness.

Standard Poodles – aesthetic disease, secondary pyoderma rare, difficult to regrow “normal” hair coat.

• Short Coated Breeds – occasionally “cured” by treatment.

Lupoid onychodystrophy

• Pathogenesis

• Unknown

• Suspected to be a lupus-like, immune-mediated disease

• Secondary bacterial paronychia common (esp. Staphylococcus intermedius)

• A possible “novel” reaction pattern to “common” underlying diseases

• Food Allergy

• Atopic Dermatitis

• Clinical Features

• German Shepherd dogs predisposed

• Acute onset of sloughing of one or more nails

• Nails avulse by lifting up distally from the corium, and continuing proximally to the claw fold

• Lameness associated with avulsion of each nail

• Subsequent loss of all nails may occur over several weeks to months

• Regrowth characterized by short, malformed, soft, dry, brittle nails

• Diagnosis

• Rule out potential underlying disease processes:

• CBC, Profile, U/A

• ANA, Cold Agglutinins

• Elimination diet trial testing

• Intradermal skin testing

• Macerated tissues culture of nail

• Bacterial culture and sensitivity

• Fungal culture

• Nail biopsy techniques:

• P3 amputation

• Longitudinal punch biopsy (8 mm)

• Nail trim flush to the nail fold

• Histopathology:

• Hydropic degeneration of basal cells

• Lichenoid interface dermatitis

• Treatment

• Treat underlying disease process if possible

• Hypoallergenic diets

• Allergen-specific Immunotherapy (ASIT)

• Essential fatty acid supplements - Derm Caps SID

• Vitamin E - 400-800 IU's – BID

• Tetracycline and Niacinamide - 10 mg/lb of each TID

• Doxycycline – 5-10 mg/kg SID (with or without concurrent Niacinamide)

• Biotin (Appearex®) – 2.5 mg/dog SID

• Pentoxifylline – 15-30 mg/kg TID

• Cyclosporine – 5 mg/kg SID

• Systemic antibiotics based on culture and sensitivity for secondary paronychia

• Cephalexin - 15 mg/lb BID x 2-4 months

• Prognosis

• Possible cure if underlying disease process is identified and treated

• Food Allergy – lifelong hypoallergenic diets

• Atopic Dermatitis – lifelong ASIT

• Discontinuation of therapy invariably results in relapses

• Regrown nails are usually malformed, soft, and friable

• Process of avulsing nails and lameness is halted