Cutaneous Manifestations of Connective Tissue Diseases

Differential Diagnosis

• Lupus  (SLE vs Cutaneous LE) 50-90% have skin lesions-rivals arthralgias, fever, weight loss, organ dz-20-30% present with urticaria
• Dermatomyositis (Adult vs Childhood)
• Scleroderma
• Mixed and undifferentiated CT disorders

Dermatmyositis

Groups:

• Group 1:  Polymyositis alone
• Group 2:  Dermatomyositis
• Group 3:  PM or DM assoc w underlying neoplasm
• Group 4:  Myositis as feature of anther CTD
• Group 5:  Childhood DM

Dermatomyositis

Common Features

• Heliotripic rash (subltle rash/puffiness around the eyes)
• Gottrin's papules (erythematous plaques over knuckles) is pathognomonic
• Bx muscle: lymphocytes between muscle bundles 

Discoid Lupus

• Predilection for scalp, face, ear (sun exposed)
• Well demarcated plaques w pigmentation changes
• 10% convert to SLE

Leukocytoclastic Vasculitis

• HSP: Bstrep assoc  Sx vasc rash, fever, abdom colic
• Cutaneous systemic angiitis:small vessles, assoc with drugs, infection, CTD
• Palpable purpuric lesions, sometimes hemorrhagic or necrotic
• More common in LE

Urticarial Vasculitis

• Fixed urticarial lesions (cayenne pepper stain to skin) ? bruising
• Arthralgia, low complement, high ESR
• More common in females
• Generally benign, no increased risk of CTD

ANCA

• c-ANCA:  Wegner's  40-90% (12-20% wi p-ANCA)
• p-ANCA:  Churg-Strauss (pulmonary), +/- Sjogrens, RA, SLE)

Eczematous Skin Disease

Definition:  a general term for scaly, chronic subacute dermatitis

• NOT synonymous  with Atopic Dermatitis
• typically clustered papulo-vesicles

• Atopic dermatitis
• Hand dermatitis
• Dyshydrotic eczema
• Numular eczema

Eczematous Skin Disease

Histology

Always present at some stage:

• spongiosis (epidermal edema) with acanthosis
• superficial perivascular lympho-histiocytic infiltrate

Secondary changes from scratching:

• Excoriations, hemorrhage
• Sub-epidermal fibrinoid changes
• Lichenification
• Secondary infections

Exogenous Causes of Eczema

• Contact Dermatitis:  irritant, allergic or photo-allergic
• Infective Dermatitis ie fungal, dermatophyte
• Post-traumatic

• Atopic dermatitis
• Seborrheic dermatitis-scalp, facial margins especially nasolabial margins*
• Asteototic dermatitis-winter itch
• Nummular dermatitis-limbs>trunk, round, demarkated
• Eczematous drug reactions
• Eczema assoc w systemic disease ie lupus

*lupus malar rash on cheeks, SPARES nasolabial area

Hand Dermatitis

• Irritant contact dermatitis
• Allergic contact dermatitis
• Dyshydrotic eczema (dry/peeling esp in winter)
• Atopic dermatitis
• Scabies!!

Parapsoriasis

• Not as thick/deep as psoriasis
• Persistent scaly plaques
• May be a precursor to Mycosis Fungiodes
• If in doubt--biopsy

Lichen Simplex Chronicus/

Prurigo Nodularis

• Secondary to chronic scratching and rubbing
• Neurodermatitis vs atopic dermatitis
• 'Picker's Nodules' form: Prurigo Nodularis
• ? Atopy
• ? Role of stress

Systemic Allergic Contact Dermatitis

• Local or generalized inflammatory skin disease in CONTACT SENSITIZED individuals when exposed to the hapten orally, transcutaneously, IV or inhaled
• 'Baboon' distribution: axillae, buttocks, thighs
• ie hydrocortisone, benadryl, neomycin, sulfa, thiuram/antibuse

Contact Sensitzer/Systemic reactions

Colophony, Balsam of Peru, Fragrance mix

Systemic reaction to:

• Spices:  cloves, nutmeg,cinnamon, cayenne

Contact Sensitzer/Systemic reactions

Ethylenediamine

• Aminophylline
• Piperazine and ethanolamine (ie hydroxyzine, meclizine, cetirizine/zyrtec?   Xyzal?

Contact Sensitzer/Systemic reactions

Nickel

Systemic reaction to:

• Nickel in tap water, utensils and food