Pityriasis Capitis: Definition and Management
Pityriasis capitis, commonly known as dandruff, is a chronic scalp condition characterized by scaling, sometimes accompanied by itching and redness, caused by the overgrowth of Malassezia yeast on the scalp. 1 It is a form of seborrheic dermatitis limited to the scalp that affects a significant portion of the world population.
Clinical Features
- Presentation: Characterized by white or grayish flakes of dead skin cells that shed from the scalp
- Associated symptoms: May include:
- Scalp itching
- Mild redness
- Scaling that ranges from fine to coarse
- Greasy or dry appearance of flakes
Pathophysiology
The condition involves several key factors:
- Microbial cause: Primarily associated with Malassezia yeast (formerly known as Pityrosporum ovale or P. orbiculare) 2
- Contributing factors:
- Sebaceous secretion (oily skin)
- Abnormal immune responses
- Host epidermal conditions
- Structural changes in the stratum corneum 1
Differential Diagnosis
It's important to distinguish pityriasis capitis from tinea capitis (scalp ringworm):
- Tinea capitis: A fungal infection of scalp hair follicles caused by dermatophyte fungi (Microsporum and Trichophyton species) 3
- Presents with patchy hair loss, scaling, and erythema
- May have inflammatory variants (kerion)
- Primarily affects preadolescent children
- Requires oral antifungal treatment
Treatment Options
Antifungal shampoos are the mainstay of treatment for pityriasis capitis, with combination products containing both antifungal agents and keratolytics showing superior efficacy. 4
First-line treatments:
- Antifungal shampoos containing:
- Zinc pyrithione (1%)
- Ketoconazole (2%)
- Piroctone olamine (0.75%) combined with salicylic acid (2%) - shown to be slightly more effective than zinc pyrithione 4
- Selenium sulfide
- Ciclopiroxamine
Application method:
- Apply shampoo to affected scalp
- Leave on for 5-10 minutes before rinsing
- Use 2-3 times weekly for 4 weeks 4, 5
- Then reduce to maintenance frequency (once weekly or biweekly)
For resistant cases:
- Consider stronger formulations or combination products
- Shampoos containing econazole 1% have shown efficacy comparable to zinc pyrithione 6
- Plant-based treatments like standardized extract of Solanum chrysotrichum have shown effectiveness comparable to 2% ketoconazole in clinical trials 5
Prevention and Management of Recurrence
Pityriasis capitis tends to be chronic and recurrent. Prevention strategies include:
- Regular use of antifungal shampoo (once weekly or biweekly)
- Addressing predisposing factors:
- Managing oily scalp
- Reducing stress
- Maintaining proper scalp hygiene
Treatment Efficacy
Clinical studies have demonstrated:
- Both zinc pyrithione and piroctone olamine with salicylic acid significantly reduce dandruff severity 4
- The combination of piroctone olamine and salicylic acid appears slightly more effective than zinc pyrithione alone 4
- Standardized plant extracts may offer alternative treatment options with good tolerability 5
Important Considerations
- Pityriasis capitis is not the same as tinea capitis, which requires oral antifungal treatment 3
- Treatment should be continued even after visible flakes disappear to prevent quick recurrence
- The condition is chronic, and patients should be educated about the need for maintenance therapy
Remember that while pityriasis capitis is primarily a cosmetic concern, it can significantly impact quality of life through social embarrassment and discomfort. Effective management typically requires ongoing maintenance therapy to control symptoms long-term.