Diagnosis: Fibroelastolytic Papulosis of the Neck (FEPN)
The most likely diagnosis is fibroelastolytic papulosis of the neck (FEPN), a benign age-related dermatosis characterized by loss of elastic fibers in the papillary dermis, and the recommended management is reassurance with symptomatic treatment for pruritus, as no curative therapy exists.
Clinical Reasoning
The presentation of bilateral, skin-colored, solid papules on the lateral neck with mild pruritus in what appears to be an adult patient is highly characteristic of FEPN. This condition encompasses what was previously described as white fibrous papulosis of the neck and pseudoxanthoma elasticum-like papillary dermal elastolysis 1, 2, 3.
Key Diagnostic Features
The clinical description matches FEPN precisely:
- Location: Lateral aspects of the neck (classic distribution)
- Morphology: Skin-colored, raised, solid papules (not vesicular)
- Bilateral distribution: Symmetric involvement
- Mild pruritus: Can be asymptomatic or mildly pruritic 3
- Solid, nonvesicular nature: Rules out infectious etiologies
Differential Diagnosis Considerations
The provided evidence addresses several conditions that can be excluded:
Drug-induced papulopustular eruptions (from EGFR inhibitors, MEK inhibitors) present with pustules and typically affect the face, scalp, upper chest and back—not isolated to the lateral neck 4. These are also associated with anticancer therapy, which is not mentioned in this case.
Infectious causes like furuncles or carbuncles present as painful, tender, fluctuant nodules with surrounding erythema 5—not matching the solid, non-tender papules described.
Multiple perifollicular fibromas can mimic this presentation but are less common and typically require biopsy for definitive diagnosis 6.
Diagnostic Workup
Confirmation requires punch biopsy showing:
- Decreased or absent elastic fibers in the papillary dermis (demonstrated with Verhoeff-Van Gieson stain) 1, 3
- Normal or slightly increased dermal collagen 2, 3
- Regular epidermis without vacuolar degeneration
- Negative Von Kossa stain (excludes pseudoxanthoma elasticum)
- Negative PAS stain (excludes fungal infection)
The histopathology distinguishes FEPN from true pseudoxanthoma elasticum, which shows calcified elastic fibers 1.
Management Approach
Primary Management
Reassurance is the cornerstone of management, as FEPN is a benign manifestation of intrinsic aging with no malignant potential 2, 3.
Symptomatic Treatment for Pruritus
For the mild pruritus described, follow this algorithmic approach:
Grade 1 (Mild, localized pruritus):
- Topical moderate-to-high potency corticosteroids (e.g., mometasone furoate 0.1% ointment or betamethasone) 4
- Gentle skin care with alcohol-free moisturizers twice daily, preferably urea-containing (5-10%) 4
- Avoid hot water, skin irritants, and excessive sun exposure 4
If pruritus persists or worsens (Grade 2):
- Continue topical corticosteroids OR
- Add oral antihistamines OR
- Consider GABA agonists (pregabalin/gabapentin) 4
Experimental Approaches
One hypothesized approach is topical antioxidants to reduce free-radical induced aging, though this lacks robust evidence 2.
Important Caveats
Do not pursue aggressive treatment: Previous failed attempts with topical corticosteroids, antifungals, and calcineurin inhibitors (as noted in similar cases 1) confirm that FEPN does not respond to these therapies when used for the underlying condition—only for symptomatic pruritus relief.
Avoid misdiagnosis pitfalls:
- Do not treat as viral warts—histopathology shows no viral cytopathic changes 6
- Do not confuse with drug-induced eruptions unless patient is on targeted cancer therapy
- Do not mistake for infectious processes requiring antibiotics
The solid, nonvesicular nature explicitly excludes vesicular conditions like eczema herpeticum 7, which would present with monomorphic vesicles and punched-out erosions.