Treatment for Cyst vs Folliculitis on the Back
For folliculitis on the back, incision and drainage is NOT indicated—treatment consists of topical antibiotics like clindamycin applied twice daily, whereas epidermoid cysts require incision, thorough evacuation of pus, and probing to break up loculations, with systemic antibiotics rarely necessary unless extensive cellulitis or systemic symptoms are present. 1
Folliculitis Management
Folliculitis is a superficial inflammation of the hair follicle that presents as 1mm-wide vesicles, pustules, or papulopustules, most commonly caused by Staphylococcus aureus, though the presence of superficial pustules does not always imply infection. 2, 3
Treatment Approach for Folliculitis:
- Apply topical clindamycin phosphate solution, lotion, or gel twice daily to the affected area as first-line therapy 4
- Systemic antibiotics are not routinely indicated for uncomplicated folliculitis 1
- For recurrent cases, consider nasal S. aureus colonization and apply mupirocin ointment twice daily in the anterior nares for the first 5 days each month, which reduces recurrences by approximately 50% 1
Key Clinical Pitfall:
Do NOT perform incision and drainage for folliculitis—this is a superficial process where inflammation is in the epidermis, unlike deeper abscesses. 1 Cytology can be performed as a simple, rapid diagnostic method to confirm bacterial etiology and rule out fungal, viral, or parasitic causes before committing to prolonged antibacterial therapy. 2
Epidermoid Cyst Management
Epidermoid cysts (often mislabeled "sebaceous cysts") contain skin flora even when uninflamed, and inflammation occurs as a reaction to cyst wall rupture rather than true infection. 1
Treatment Approach for Inflamed Epidermoid Cysts:
- Incision and thorough evacuation of pus is the definitive treatment 1
- Probe the cavity to break up loculations 1
- Simply cover the surgical site with a dry dressing—this is usually the easiest and most effective wound treatment, though some clinicians pack with gauze or suture closed 1
- Gram stain, culture, and systemic antibiotics are rarely necessary 1
Exceptions Requiring Systemic Antibiotics:
Systemic antibiotics are indicated ONLY when: 1
- Multiple lesions are present
- Cutaneous gangrene develops
- Severely impaired host defenses exist
- Extensive surrounding cellulitis is present
- Severe systemic manifestations occur (high fever)
Distinguishing Features
The critical distinction is anatomical location and depth:
- Folliculitis: Superficial inflammation at the follicular opening or perifollicular area, with pus in the epidermis 3
- Epidermoid cyst: Collection of pus within the dermis and deeper skin tissues, presenting as painful, tender, fluctuant red nodules with surrounding erythema 1
On the back, both conditions can coexist—epidermoid cysts may develop secondary folliculitis, but the treatment paradigm remains distinct: surgical drainage for the cyst component and topical antibiotics for any superficial follicular inflammation. 1, 5