Eczema (Atopic Dermatitis)

Pathophysiology

Type I hypersensitivity: IgE-mediated allergic reaction sensitizing mast cells to release histamine
Barrier deficiency: Deficiency in certain fatty acids compromises the skin's lipid layer
Stress increases cortisol. Chronic stress depletes cortisol, making inflammation harder to control
Major types: Atopic dermatitis (most common; red, flaky, dry in skin creases), seborrheic eczema (yellowish/oily patches), dyshidrosis (fluid-filled blisters on hands/feet)
The hygiene hypothesis: Overprotecting children from allergens may interfere with immune development

Intense pruritus and the "itch-scratch cycle" (scratching stimulates more itching and tissue damage)
Typical sites: creases of elbows, knees, wrists, sides of nose
Bilateral distribution (e.g., both elbows) — helps distinguish from unilateral fungal infections
Lichenification: thickened, leathery skin from chronic scratching
Acute: redness, swelling, vesicles that may weep or ooze
Secondary infection sign: Honey-colored crusts or spreading redness (impetigo) requiring referral

Honey-colored crusts on eczematous skin: Secondary bacterial infection (impetigo) — medical referral
Acute weeping/blistered lesions: Locally contraindicated for massage
Unilateral lesion: Consider tinea (fungal) rather than eczema
Distinguish from psoriasis: Eczema is in flexor creases. Psoriasis is on extensor surfaces with silvery scale

Acute lesions (weeping/blistered): Locally contraindicated — skin is not intact
Chronic lesions (dry/scaly): Precaution. Gentle massage with hypoallergenic lubricant may be tolerated
Lubricant patch test: Essential — apply to unaffected skin (inner forearm) and wait 30 minutes
Use hypoallergenic, nut-free products; avoid omega-6-rich oils (almond, sunflower, soy) in severely allergic clients — break down to pro-inflammatory arachidonic acid on skin
Massage increases local circulation, which may exacerbate itching — avoid red, hot areas
Relaxation massage to lower sympathetic arousal is beneficial for reducing stress-induced flares
Topical corticosteroids: Can cause skin fragility — use gentle pressure over treated areas

Morphology determines management: weeping/blistered = contraindicated. Dry/scaly = precaution
Bilateral distribution distinguishes eczema from unilateral fungal infections
Lubricant patch test (30 minutes on unaffected skin) rules out hypersensitivity
The atopic triad: eczema, asthma, allergic rhinitis
Honey-colored crusts signal secondary impetigo requiring medical referral

Eczema is a Type I IgE-mediated hypersensitivity causing the itch-scratch cycle and bilateral distribution in skin creases
Acute (weeping/blistered) lesions are locally contraindicated. Chronic (dry/scaly) lesions are a precaution
Lubricant patch testing is essential before treatment
Hypoallergenic, nut-free products are required. Avoid omega-6-rich oils in severely allergic clients
Stress reduction through relaxation massage can reduce flare frequency