Can Keratosis Pilaris Occur on the Chest and Abdomen?
Yes, keratosis pilaris can occur on the chest and abdomen, though these are not the typical locations for this condition.
Classic Distribution Pattern
Keratosis pilaris (KP) most commonly affects specific anatomical sites:
- Primary locations: The extensor aspects of the upper arms, upper legs, and buttocks are the most frequently affected areas 1
- Facial involvement: KP can present on the face, particularly in variants like erythromelanosis follicularis faciei et colli 2
- Extremities: The follicular hyperkeratosis typically involves the extremities 3
Atypical Presentations on Trunk
While the chest and abdomen are not classic sites, KP can present in these locations:
- Generalized distribution: Case reports document generalized keratosis pilaris affecting broader body surface areas, including the trunk 4
- Variant presentations: In Langerhans cell histiocytosis (LCH), cutaneous manifestations may occur as an erythematous papular rash located on the abdomen, chest, or back, though this represents a different histiocytic disorder rather than true KP 3
- Associated conditions: In cardio-facio-cutaneous syndrome, keratosis pilaris is seen in the majority of cases and can affect the face and extremities 3
Clinical Characteristics
The appearance remains consistent regardless of location:
- Morphology: Small, folliculocentric keratotic papules with variable perifollicular erythema 2
- Texture: The papules create a stippled appearance resembling gooseflesh 1
- Symptoms: Usually asymptomatic, with complaints limited to cosmetic appearance or mild pruritus 1
Diagnostic Considerations
When evaluating suspected KP on the chest or abdomen:
- Rule out drug-induced causes: In patients on chemotherapy, BRAF inhibitors, or MEK inhibitors, consider palmar-plantar erythrodysesthesia syndrome (PPES) or hand-foot skin reaction, which can present with hyperkeratosis but follows a different distribution pattern 5
- Exclude other papular eruptions: The differential includes lichen spinulosus, phrynoderma, and trichostasis spinulosa 2
- Consider systemic associations: Evaluate for ichthyosis vulgaris, palmar hyperlinearity, and inherited FLG or ABCA12 gene mutations 2
Management Approach
Treatment remains the same regardless of body location:
- First-line therapy: Topical keratolytic agents such as urea (indicated for keratosis pilaris) 6, followed by topical retinoids and corticosteroids 2
- General measures: Hydrating skin, avoiding long baths or showers, and using mild soaps or cleansers 2
- Refractory cases: Consider laser therapy (particularly QS:Nd YAG laser) or microdermabrasion 7, 8