Red Itchy Bumps with Pus: Differential Diagnosis & Management

Pustular, pruritic papules have a focused differential. Distribution, exposure history, and systemic signs narrow diagnosis.

Common Causes

Condition	Key Features	Typical Sites	Treatment
Folliculitis (bacterial: S. aureus; fungal: Malassezia; Pseudomonas hot tub)	Pustules centered on hair follicles; ± pain	Scalp, beard, axilla, buttocks, thighs	Topical/oral antibiotics, antifungals; avoid occlusion
Acne vulgaris	Comedones + papules/pustules/nodules	Face, chest, back	Retinoids, benzoyl peroxide, antibiotics, isotretinoin
Ingrown hairs (pseudofolliculitis)	Post-shave; papules/pustules with visible trapped hair	Beard, neck, bikini, legs	Stop shaving, laser, chemical exfoliants, topical retinoids
Boils (furuncles/carbuncles)	Deep, tender, fluctuant nodules; may drain	Any hair-bearing area	Incision & drainage ± antibiotics
Impetigo	Honey-crusted erosions; contagious	Face, extremities (kids)	Topical mupirocin; oral if extensive
Scabies	Burrows, intense nocturnal itch; pustules if superinfected	Web spaces, wrists, belt, genitalia	Permethrin 5% / ivermectin
Contact dermatitis (secondary infection)	Vesicles → pustules; history of exposure	Exposed areas	Remove allergen, topical steroids ± antibiotics

Red Flags – Seek Care

• Spreading erythema, warmth, streaking (cellulitis)
• Fever, systemic symptoms
• Immunocompromised, diabetic
• Near eye, rapid progression
• Recurrent despite treatment

General Skin Care

• Gentle cleansing, avoid scrubbing
• Loose, breathable clothing
• Don't squeeze – spreads infection, scars
• Clean razors, shave with grain

Accurate diagnosis requires clinical exam ± culture. Self-treatment with wrong agent worsens condition.