Annular eruption on the lower leg - Clinical Advisor

Annular eruption on the lower leg

Slideshow

  • Slide

An otherwise healthy 38-year-old woman presented to the dermatology clinic with a several-month history of a slightly itchy, expanding rash on the lower leg. Treatment with a topical corticosteroid when the rash first appeared helped the itch but seemed to make the rash slightly worse.

Treatment with a topical antifungal several weeks before presentation was also unsuccessful. Examination revealed erythematous pustules and few deeper-seated nodules on the left lower leg in an annular configuration.



HOW TO TAKE THE POST-TEST: This Clinical Advisor CME activity consists of 4 articles. To obtain credit, you must also read Scaly plaques after 
onychomycosis therapy
, Crateriform nodule on a cyclist, and Enduring eruption of papules on the chest. Then take the post-test here.


The patient's diagnosis was confirmed by performing a potassium hydroxide preparation of the affected skin, which revealed fungal hyphae. Of note, if this test had been done while the patient had been using the topical antifungal or shortly thereafter, it...

Submit your diagnosis to see full explanation.

The patient’s diagnosis was confirmed by performing a potassium hydroxide preparation of the affected skin, which revealed fungal hyphae. Of note, if this test had been done while the patient had been using the topical antifungal or shortly thereafter, it may have yielded a false-negative result. Given the clinical appearance with deeper-seated lesions, the presence of fungal elements on the potassium hydroxide preparation, and the lack of response to topical antifungals, the patient was diagnosed with Majocchi granuloma, a cutaneous infection caused by dermatophytosis of the hair follicle.


The condition was first described in 1883 by Domenico Majocchi, who named it granuloma tricofitico to indicate the causative organism at the time, Trichophyton tonsurans, and the granulomatous inflammatory infiltrate seen in association with the hair follicle.1,2

Two forms of Majocchi granuloma exist. The first is a superficial variant consisting of asymptomatic papules and pustules. It is most common in immunocompetent patients, particularly women who frequently shave their legs. The act of hair removal disrupts the follicular anatomy, making it susceptible to infection and subsequent occlusion.2

The second type of Majocchi granuloma is clinically characterized by tender, deeper-seated plaques and nodules. It is most common in immunocompromised patients. As organisms proliferate, follicular rupture may occur, causing introduction of fungal elements into the dermis and occasional abscess formation.3,4

Skin lesions of Majocchi granuloma are generally asymptomatic. The typical appearance is that of erythematous papules, pustules, or nodules, arranged in an annular configuration. If a patient has recently used a topical emollient, steroid, or antifungal, scales may be absent. 

The lower extremity is the body site most commonly affected by Majocchi granuloma, but other areas of involvement may include the scalp, face, forearms, inguinal creases, and genitals.5,6Without treatment, the rash persists and can lead to scarring.2,7

The rash often begins as classic tinea corporis (ringworm), with an annular, erythematous plaque with scale at the border. Over time, if the infection persists or is left untreated, the fungus may infiltrate more deeply into the hair follicle with a resulting alteration in clinical appearance. 


Having a chronic superficial fungal infection of the skin or nails predisposes patients to the development of Majocchi granuloma. If a topical steroid is then applied to this infection, there can be an increase in the number of fungal hyphae on the skin.5,8 

In addition, increased heat, moisture, and use of topical preparations can occlude the hair follicle, creating an ideal environment for the fungus to proliferate.2,9Immunosuppression (either iatrogenic or due to underlying medical conditions) is also a risk factor for development of Majocchi granuloma.3,10,11

The most common dermatophyte cultured from lesions of Majocchi granuloma isTrichophyton rubrum. Other reported causative species includeT. mentagrophytes,T. tonsurans,T. verrucosum,Microsporum canis, andEpidermophyton floccosum.

Trauma to the skin is usually the inciting event that allows keratin to be introduced into the dermis, thus providing a substrate for dermatophytes.2,5 

As the inflammatory reaction to the keratin and the dermatophyte (both of which are seen as foreign material within the dermis) occurs, cellular destruction and amounts of stromal acid mucopolysaccharide increase. The acidic environment then creates a more hospitable medium for hyphae growth.10 

Macrophages also play a key role in dermatophyte destruction, but corticosteroids inhibit the ability of the macrophages to perform this role.2

The diagnosis can often be made by scraping the affected skin onto a glass slide, adding potassium hydroxide, gently heating, and examining under a microscope. This simple bedside test will reveal fungal hyphae, but sometimes the hyphae do not appear in their usual forms.10

When this test is inconclusive or negative, obtaining a tissue specimen for biopsy or tissue culture is indicated. Histopathologic examination of an early lesion shows suppurative folliculitis. Over time, later lesions demonstrate perifollicular granulomatous inflammation and dermal abscesses.7 

Frequently, there is an infiltrate of eosinophils, histiocytes, keratin, and foreign body giant cells.7,12Alopecia may also be apparent. Fungal elements are highlighted with Periodic Acid-Schiff (PAS) and Gomori methenamine silver (GMS) staining.2,10,11

While the appearance of Majocchi granuloma is fairly characteristic, other entities may mimic its clinical presentation. The differential diagnosis is discussed herein: Acne vulgaris tends to preferentially affect the face, and patients will also have comedones. 

Bacterial folliculitis can present on any hair-bearing surface, and usually consists of follicular-based pustules. Doing a culture of the purulent material is helpful. For the deeper variant of Majocchi granuloma, lesions may look like erythema nodosum, an inflammatory condition of the subcutaneous fat occurring on the anterior shins. 

Erythema nodosum occurs as a reaction either to a medication or to another systemic condition and consists of tender subcutaneous nodules. Cutaneous sarcoidosis can present in a number of different ways, but lesions are usually smooth, violaceous, sometimes annular plaques that are often seen on the face but can occur anywhere on the body. 

It is seen more commonly in African-American patients, and the lungs are the most commonly involved extracutaneous site. If the diagnosis is unclear, a biopsy should be done. 


Most cases of Majocchi granuloma fail to respond to topical antifungal therapy due to poor penetration into the deeper portions of the follicular unit.6 

For this reason, systemic antifungals are usually required for a duration of at least 4 to 8 weeks, with most lesions resolving within 6 weeks.2In immunocompromised patients, longer treatment courses may be necessary.

Our patient was treated with oral terbinafine for 4 weeks and showed rapid improvement without residual scarring. The patient had experienced no recurrence after 1 year.


Kaitlyn Powell is a fourth-year medical student at Virginia Commonwealth University in Richmond, Virginia. Erin Reese, MD, is an assistant professor of dermatology at Virginia Commonwealth University.



HOW TO TAKE THE POST-TEST: This Clinical Advisor CME activity consists of 4 articles. To obtain credit, you must also read Scaly plaques after 
onychomycosis therapy
, Crateriform nodule on a cyclist, and Enduring eruption of papules on the chest. Then take the post-test here.


References


  1. Saadat P, Kappel S, Young S, et al. Aspergillus fumigatus Majocchi’s granuloma in a patient with acquired immunodeficiency syndrome. Clin Exp Dermatol. 2008;33(4):450-453.
  2. Ilkit M, Durdu M, Karakas M. Majocchi’s granuloma: a symptom complex caused by fungal pathogens. Med Mycol. 2012;50(5):449-457.
  3. Gupta S, Kumar B, Radotra BD, Rai R. Majocchi’s granuloma trichophyticum in an immunocompromised patient. Int J Dermatol. 2000;39(2):140-141.
  4. Gill M, Sachdeva B, Gill PS, et al. Majocchi’s granuloma of the face in an immunocompetent patient. J Dermatol. 2007;34(10):702-704.
  5. Bae BG, Kim HJ, Ryu DJ, et al. Majocchi granuloma caused by Microsporum canis as tinea incognito. Mycoses. 2011;54(4):361-362.
  6. Cho HR, Lee MH, Haw CR. Majocchi’s granuloma of the scrotum. Mycoses. 2007;50(6):520-522.
  7. Arenas R, Toussaint S, Isa-Isa R. Kerion and dermatophytic granuloma. Mycological and histopathological findings in 19 children with inflammatory tinea capitis of the scalp. Int J Dermatol. 2006;45(3):215-219.
  8. Elgart ML. Tinea incognito: an update on majocchi granuloma. Dermatol Clin. 1996;14(1):51-55.
  9. Hazelrigg DE, Williams TE, Rudolph AH. Nodular granulomatous perifolliculitis. JAMA. 1975;233(3):270-271.
  10. Smith KJ, Neafie RC, Skelton HG 3rd, et al. Majocchi’s granuloma. J Cutan Pathol. 1991;18(1):28-35.
  11. Tateishi Y, Sato H, Akiyama M, et al. Severe generalized deep dermatophytosis due to Trichophyton rubrum (trichophytic granuloma) in a patient with atopic dermatitis. Arch Dermatol. 2004;140(5):624-625.
  12. Grossman ME, Pappert AS, Garzon MC, Silvers DN. Invasive Trichophyton rubrum infection in the immunocompromised host: report of three cases. J Am Acad Dermatol. 1995;33(2 Pt 1):315-318.
Next hm-slideshow in Clinical Quiz