What conditions cause alopecia accompanied by a tender scalp?

Hair Loss with Tender Scalp: Key Causes

The most important condition to consider when hair loss is accompanied by scalp tenderness is kerion—a severe inflammatory variant of tinea capitis that presents as a painful, boggy mass with alopecia and requires urgent systemic antifungal therapy to prevent permanent scarring. 1

Primary Inflammatory Causes

Kerion (Tinea Capitis)

• Kerion presents as a painful, boggy, inflammatory mass with associated alopecia, studded with pustules and matted with thick crust, often accompanied by regional lymphadenopathy. 1

• This represents a delayed host inflammatory response to dermatophyte fungi, most commonly caused by zoophilic species (T. mentagrophytes, T. verrucosum) or endothrix infections (T. tonsurans, T. violaceum). 1

• Kerion is frequently misdiagnosed as bacterial abscess, but secondary bacterial infection should not be overlooked. 1

• Fungal culture is mandatory before treatment, and oral antifungal therapy is required—topical treatment alone is insufficient. 1, 2

• If kerion is strongly suspected clinically based on scaling, lymphadenopathy, or alopecia, it is reasonable to start therapy immediately without waiting for culture results to prevent scarring. 1

Diffuse Pustular Tinea Capitis

• In more inflammatory variants of tinea capitis, diffuse patchy alopecia may coexist with scattered pustules or low-grade folliculitis, associated with painful regional lymphadenopathy. 1

Perifolliculitis Capitis Abscedens et Suffodiens (PCAS)

• PCAS is a rare chronic suppurative and inflammatory scalp disease presenting with tender, fluctuant nodules and abscesses with draining pus and patchy alopecia. 3

• This condition is difficult to treat, with isotretinoin showing excellent response in case reports. 3

Secondary Inflammatory Causes

Favus (Chronic Inflammatory Tinea Capitis)

• Favus, typically caused by T. schoenleinii infection, is characterized by yellow, crusted, cup-shaped lesions (scutula) that develop around follicular openings and may result in cicatricial (scarring) alopecia. 1

• This variant is most commonly encountered in the Middle East and North Africa. 1

Alopecia Areata with Inflammation

• While alopecia areata is typically non-inflammatory, zoophilic or geophilic Microsporum species can demonstrate intense inflammatory response with scalp tenderness. 1

Diagnostic Algorithm

Step 1: Clinical Examination

• Look for boggy, tender masses with pustules and crusting (kerion) versus patchy alopecia with fine scaling (non-inflammatory tinea capitis). 1

• Check for regional lymphadenopathy, which is common with kerion and diffuse pustular variants. 1

• Examine for exclamation mark hairs (pathognomonic for alopecia areata) versus broken-off hair stubs (black dot tinea capitis). 1, 2

Step 2: Laboratory Confirmation

• Obtain fungal culture by plucking hairs, using a blunt scalpel to remove hair and scalp scale, or taking scalp brushings—this is essential before initiating treatment. 1, 2

• Wood's lamp examination may identify M. canis infections through fluorescence, though most common organisms (T. tonsurans, T. violaceum) do not fluoresce. 1

• Skin biopsy is reserved for uncertain diagnosis or suspected scarring alopecia. 1, 2

Step 3: Treatment Initiation

• For suspected kerion, start oral antifungal therapy immediately (griseofulvin 20-25 mg/kg daily for 6-8 weeks) without waiting for culture results to prevent permanent scarring. 1

• Topical antifungal shampoos (ketoconazole 2%, selenium sulfide 1%, or povidone-iodine) should be added to reduce spore transmission but are insufficient as monotherapy. 1

Critical Pitfalls to Avoid

• Do not mistake kerion for bacterial abscess—while secondary bacterial infection can occur, the primary pathogen is fungal and requires systemic antifungal therapy, not just antibiotics. 1

• Do not rely on topical therapy alone for any form of tinea capitis—oral therapy is required to penetrate hair follicles and achieve mycological cure. 1

• Do not delay treatment in suspected kerion cases—waiting for culture results (which take 2-4 weeks) increases risk of permanent scarring alopecia. 1

• Do not overlook the psychological impact of visible scalp lesions and hair loss, which may warrant mental health assessment. 2, 4