scalp pustules are a relatively common problem and often recurrent
there are many causes and the various conditions can be divided in to those causing superficial pustules or vesicles vs those causing deeper granulomas
poorly understood pruritic condition which is mainly due to Cutibacterium acnes but also there may be a role for yeasts (Malassezia species) and mites (Demodex folliculorum)
unlike the more severe cicactrical acne necrotics variant below, it leaves no scars, is confined to the scalp, and is characterized by extremely itchy vesiculopustular lesions
probably has genetic and environmental predispositions
Rx is anti-dandruff shampoos (may be helpful), topical antibiotics (eg. clindamycin, fusidic acid gel) +/- steroids +/- oral antihistamines +/- short courses low dose cefalexin 500-1000mg/d +/- oral long term docycycline +/- low dose oral isotretinoin
Cutibacterium acnes is generally more sensitive to doxycline than cefalexin and resistance development appears to be low
A topical foam formulation of minocycline was approved for use in acne by the FDA in the US in 2019 and may be an option in the future
there may be an as yet unproven role for nicotinamide orally or topically 1)
a severe cicatrical form is called acne necrotica / acne varioliformis / necrotizing lymphocytic folliculitis
this is usually recurrent papules mainly on the margins of the scalp which can become pustular with depressed centers and develop black haemorrhagic crusts which last for 3-4 weeks and may leave permanent pox-like scars
thought to begin as lymphocytic folliculitis, which were triggered by Cutibacterium acnes and perhaps an abnormal inflammatory response to this bacteria or to Staph aureus
usually begins in the third decade of life or later and lacks comedones
mechanical manipulation of pre-existing lesions, such as rubbing and scratching, may aggravate the disease, but not a cause - doxepin can be considered for patients who excoriate and manipulate lesions
Rx is doxycycline 100mg po once daily plus topical steroids and usually needs to be continued for weeks or months but some do not respond 2)
however doxycycline, especially at 100mg/d appears to increase risk of resistance organisms, especially Staph. epidermidis - more so than short courses of cefalexin 3) which is also beneficial for this condition
once control is achieved, antibacterial or antiseptic lotions may substitute systemic antibiotics or isotretinoin as prophylaxis to prevent possible relapse
if Staph. auerus is found then appropriate antibiotics and nasal carriage clearance is suggested
a rare severe form is perifolliculitis capitis abscedens et suffodiens which mainly affects black adult men
recurrent episodes of eruptive sterile follicular papulopustules in seborrheic areas (including face, neck, trunk as well as scalp), accompanied by leukocytosis and eosinophilia on biopsy. Many cases have mild eosinophilia, mild rise in IgE and reduced IgG and IgA on blood tests.
classic form: more common in Japan; chronic and recurrent with individual lesions typically last more than 1-2 weeks, and relapse every 3-4 weeks but no systemic symptoms. 70-90% respond well to NSAIDs such as oral indomethacin (25–75 mg/day). Refractory cases may require UV Rx or otehr Rx.
immunosuppression-associated type of EPF - eg. HIV, leukaemia, etc
infantile form - most resolve by age 3yrs
in cases where the torso and palms are affected, consider L-tryptophan-induced form with eosinophilic-myalgia syndrome
follicular papules and indurated plaques associated with alopecia
accompanied with mycosis fungoides and angiolymphoid hyperplasia with eosinophilia, less frequently with chronic discoid lupus erythematosus and Goodpasture’s syndrome
follicular mycosis fungoides
infiltrated follicular papules located on the face, neck, trunk and extremities, and sometimes on the scalp
perifolliculitis capitis abscendens et suffodiens
severe destructive folliculitis with sinus tracts and fistulae leading to scarring alopecia
often part of the acne inversa spectrum
almost exclusively in young men
?role of Gram negative infections
secondary syphilis (rare)
folliculitis decalvans (rare)
causes tufting of hair so it looks like a toothbrush and eventually scarring and cicatricial alopecia
genetic immunodeficiencies
recurrent and persistent pyoderma, folliculitis, keratitis, and atopic dermatitis with defective leukocyte and lymphocyte function and response to antihistamines (H1)6)
deep folliculitis generally with granulomas
acne vulgaris
acne inversa group of follicular occlusion conditions
acne conglobata
dissecting cellulitis of the scalp
hidradenitis suppurativa
rare familial form which affects the post-auricular region 7)
staph furuncle/carbuncle
tinea barbae
sycosis
favus
folliculitis caused by T. schoenleinii and is currently prevalent in Spain