|  | Bites & Stings | Dog Bites

Understanding Papules: Causes, Symptoms & Treatments

A papule is a small, solid, elevated skin lesion <1 cm in diameter, with distinct borders. Color ranges from pink/red to brown/violaceous. Papules are palpable and non-follicular (unlike pustules). They are a primary morphological feature in many dermatoses.

Common Causes & Associated Conditions

ConditionTypical Papule Features
Acne vulgarisInflammatory papules on face, chest, back; may progress to pustules
Atopic dermatitis (eczema)Erythematous, pruritic papules; often excoriated, lichenified
PsoriasisWell-demarcated, silvery-scaled papules coalescing into plaques
Lichen planusViolaceous, polygonal, flat-topped papules; Wickham striae; wrists, ankles, oral mucosa
Molluscum contagiosumUmbilicated, pearly papules; viral (poxvirus); children, immunocompromised
Drug eruptionMorbilliform (measles-like) papules; symmetric, trunk-proximal; 7–14 days post-drug
Insect bitesPruritic, erythematous papules; often grouped or linear
Keratosis pilarisKeratin-filled follicular papules; upper arms, thighs; "chicken skin"

Diagnostic Approach

  1. History: Onset, progression, pruritus, pain, triggers, medications, exposures, systemic symptoms.
  2. Exam: Distribution, morphology, color, surface, arrangement (grouped, linear, diffuse).
  3. Dermoscopy: Vascular patterns, scale, pigment clues.
  4. Biopsy: If diagnosis uncertain or malignancy suspected (e.g., Bowen's disease, cutaneous lymphoma).

Treatment Principles

Target the underlying cause:

  • Inflammatory: Topical corticosteroids, calcineurin inhibitors, PDE4 inhibitors.
  • Infectious: Antivirals, antibiotics, antifungals, or physical removal (molluscum).
  • Acne: Retinoids, benzoyl peroxide, antibiotics, hormonal therapy.
  • Psoriasis/lichen planus: Topical steroids, vitamin D analogs, phototherapy, systemic agents.
  • Symptomatic: Emollients, antihistamines for pruritus.

When to Refer

  • Diagnostic uncertainty
  • Widespread or rapidly progressive eruption
  • Mucosal involvement
  • Systemic symptoms (fever, arthralgia)
  • Failure of first-line therapy

Dog Bites - Related Articles