19-year-old student with acneiform eruption

presented by

David Elpern MD

Williamstown, MA, USA

on November 29, 2005

Abstract The patient is a 19 yo man with a 5-year history of an acneiform eruption predominantly on the torso that did not respond to topical anti-acne agents and a number of systemic antibiotics
19-year-old man
5 years
torso and proximal extremities

19-year-old man with a 5-year history of acneiform eruption predominately on torso and proximal extremities. Some facial involvement, but less than on torso. He is in good health, no history of diabetes or steroid use. No antibiotics for months. In the past he has used benzoyl preoxide ceams and washes, topical retinoids, topical antibiotics and tetracycline and its derivatives. None has ever helped.

Physical Examination

Healthy young man with Type IV skin. On torso and proximal extremities he has discrete erythematous papules and an occasional pustule. No cysts. Face largely clear.



Laboratory Data



Histopath showed marked perifollicular lymphoneutrophilic infiltrate c/w acute folliculitis. Further cuts showed numerous PAS (+)"fungal spores" in the follicular ostia.

Diagnosis Probable pityrosporum folliculitis
Reasons Presented
  1. To hear what others think about this entity
  2. For therapeutic suggestions
  3. To raise awareness of P folliculitis
  1. Are the yeasts seen on PAS stain incidental or indicative of pityrosporum folliculitis?
  2. What is your therapeutic protocol for P folliculitis
  3. Is KOH prep enough to make diagnosis. How do you do it? I have troubled recognising the yeasts and prefer punch biopsy.
    I have started the patient on itraconazole 200 mg per day and ketoconazole 2% shampoo to torso. The literature does not have good guidelins for how to treat this; but I suspect 4 - 6 weeks worth oral medications will be necessary
  4. Please suggest diagnostic and therapeutic alternatives.

Ayers K, Sweeney SM, Wiss K. Pityrosporum folliculitis: diagnosis and management in 6 female adolescents with acne vulgaris. Arch Pediatr Adolesc Med. 2005 Jan;159(1):64-7.

BACKGROUND: Pityrosporum folliculitis is a common inflammatory skin disorder that may mimic acne vulgaris. Some adolescents with recalcitrant follicular pustules or papules may have acne and Pityrosporum folliculitis simultaneously. Clinical response is dependent on treating both conditions.

OBJECTIVES: To demonstrate the similarity in clinical manifestation between acne vulgaris and Pityrosporum folliculitis, the benefit of potassium hydroxide preparation, and the benefit of appropriate antifungal therapy.

PATIENTS: We describe 6 female adolescents with concurrent Pityrosporum folliculitis infection and acne vulgaris. INTERVENTION: A potassium hydroxide examination was performed on all 6 patients from the exudate of follicular pustules exhibiting spores consistent with yeast. All patients were treated with oral antifungals, and 5 of the 6 patients were also treated with topical antifungals.

RESULTS: Six of 6 patients improved with antifungal treatment. All patients also required some ongoing therapy for their acne.

CONCLUSIONS: These patients demonstrate that follicular papulopustular inflammation of the face, back, and chest may be due to a combination of acne vulgaris and Pityrosporum folliculitis, a common yet less frequently identified disorder. Symptoms often wax and wane depending on the patient's activities, time of the year, current treatment regimens, and other factors. Pityrosporum folliculitis will often worsen with traditional acne therapy and dramatically respond to antifungal therapy.

Comments from Faculty and Members

Azad Kassim MD, Hasa, Saudi Arabia on November 29, 2005

Presence of lesions for long time (5 years),with no response to anti-acne measures, absence of comedones and lack of scars are all make the diagnosis of pityrosporum folliculitis most likely. In such cases simple side lab. KOH test can confirm the diagnosis and further confirmation may be done by PAS stain. I totally agree that an initial oral antifungal therapy with cyclic course of itraconazole 200 mg qd for 1-2 weeks per month (1-2 cycles) or a weekly dose of 150 mg fluconazole for 4-6 weeks is a good idea. Further relapses can be prevented by maintaining patients on either ketoconanazole 2% shampoo or selenium sulfide 2.5% shampoo twice per week for 6-8 weeks then once per week for subsequent uses.

Walter G Larsen MD, Portland, OR, USA on November 29, 2005

This disease is now called Malassezia folliculitis.
In addition to the treatment prescribed I add ZNP soap since it has a tendency to recur.

Amanda Oakley FRACP, Hamilton, New Zealand on November 29, 2005

I have found a short course of isotretinoin effective for malassezia folliculitis

Janet Hickman MD, Lynchburg, VA, USA on November 29, 2005

I agree that it is difficult to identify Pityrosporum on KOH. They are more easily visualized by staining the smear with Wright Giemsa stain as you would a Tzanck smear. Nile Blue stain is even more useful, though not as apt to be available in the office.

Stephen Glinick MD, Providence, RI, USA on November 29, 2005

I believe that I have seen predominantly two presentations for this entity. First are the milder forms that look like forehead comedones but don"t respond to topical retinoids. I usually treat these patients with a two week course of Ketoconazole 200mg bid. In most cases they will have cleared and I then move them to Nizoral shampoo several times per week and topical Ketoconazole cream daily, both used chronically. Occasionally the patient will need a second course of oral Ketoconazole some months down the line if the topicals don't hold things in check. I feel that oral Ketoconazole is so reliably diagnostic that I have abandoned biopsying for confirmation. In fact, unless immunocompromised, if the patient doesn't clear with oral ketoconazole then they didn't have Pitorosporon Folliculitis to begin with. I have never found KOH to be elucidating since yeast forms can be seen even if the folliculitis component is absent. (By the way I think the term "folliculitis" is a bit misleading here because most lesions are barely inflammatory in this subset).

The second presentation is much less common and looks like bad nodulocystic acne. I have discovered these only by biopsying nodules that completely resisted conventional oral acne regimens. Usually treatment resistant acne that goes on to Isotretinoin gets at least partial control with oral antibiotics. When that has not been the case I have considered nodular pityrosporon folliculitis before embarking on Isotretinoin. I have occasionally wondered if I have actually treated some patients who really had nodular pityrosporum folliculitis with Isotretinoin thinking they had nodulocystic acne and gotten them better by default via shutting down the sebaceous glands.

Khaled El-hoshy M.D., Troy, Michigan, USA on November 30, 2005

Topical ketoconazole shampoo for 10 min qod , 2-4 weeks is usually v helpful

Omid Zargari MD, Consultant Dermatologist, Booali Medical Group, Rasht, Iran on Nov 30, 2005

Pityrisporal folliculitis (PF) vs. Acne vulgaris; in my estimation, there are some clues which help a dermatologist to differentiate these two diseases. 1) Pityrisporal folliculitis is pruritic, especially after sweating. 2) Trunk involvement and sparing of the face are among the other features of PF. 3) Furthermore, antibiotics have no role in treating PF, Indeed they make PF worse.

Concerning therapy, I believe that a combination of systemic and topical azoles would be effective therapy for PF. Another point; regarding that Malassezia are common residents of skin and have some roles in the pathogenesis of acne, sometimes I use topical antifungals in combination with routine anti-acne agents in treating acne.

Laxmisha Chandrashekar MD, India on December 12, 2005

Although a well known entity it is often overlooked. Apart from oral antifungals, I also prefer addition of topical tretinoin to the treatment regimen as the folliculitis tends to be very resistant to therapy

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