A Case of Scalp White Piedra Caused by Trichosporon Ovoides.

White piedra also known as trichomycosis nodularis or trichomycosis nodosa is a superficial fungal infection of the hair shaft caused by Trichosporon asahii. We are reporting a case of white piedra in a female for the rarity of such occurrence.

INTRODUCTION

White piedra is a superficial fungal infection of the hair shaft, caused by Trichosporon beigelii. It is also known as tinea nodosa, trichosporonosis nodosa, and trichomycosis nodularis.[1] Clinically, characterized by the presence of asymptomatic numerous, discrete, soft nodules loosely attached to the infected hair shafts, producing a sensation of grittiness. They are microscopic, with about 0.5 mm in diameter. Coalescence results in a sleeve-like mass indistinguishable from trichomycosis axillaris.[2] Commonly involved sites are distal portions of facial, beard, moustache and pubic hairs, with the scalp being rarely involved.[1] In contrast, black piedra almost always occurs on the scalp hair.

CASE REPORT

A 32-year-old Muslim female presented in our skin outdoor for the evaluation of asymptomatic palpable nodules along the scalp hairs since 3 months. She had been using henna mehndi for 2 years and had a history of tying wet hairs after washing. Other hairy parts of the body and scalp skin were normal. There was no pediculosis. There was no history of similar involvement in family members.

On clinical examination, scalp hairs were normal-looking without evidence of sparseness. However, individual hair showed barely visible but well-palpable whitish to cream-colored, easily detachable nodules of size 1–1.5 mm present over the shaft of almost all the scalp hairs, distributed at irregular intervals and not easily movable along the hair shaft [Figure 1].

Figure 1

Dermoscopic view of affected hair showing whitish to cream-colored nodules adherent to scalp hair

Hair pull test result was negative. Wood's lamp examination of the affected and uninvolved hairs did not show any fluorescence. Potassium hydroxide 10% wet mount of the affected hair revealed clusters of blastoconidia were present intermittently along the hair shaft [Figure 2].

Figure 2

Potassium hydroxide 10% wet mount of the affected hair revealing clusters of blastoconidia

Growth on Sabouraud agar at 37°C and 22°C showed soft whitish to cream-colored wrinkled colonies at the end of 1 week [Figure 3a].

Figure 3

(a) Creamy white wrinkled cerebriform colony on Sabouraud dextrose agar, (b) Fungal arthrospore seen on lactophenol cotton blue (×400), (c) Pink color on urease test indicating a positive reaction

The lactophenol cotton blue mount of the isolate showed pleomorphic yeast cells and septate hyphae fragmenting to form rectangular arthrospores and blastoconidia [Figure 3b]. Therefore, on the basis of macroscopic findings, microscopic findings, and urease test positivity [Figure 3c] identity of T. beigelii complex had been confirmed.

The patient was treated with topical 2% ketoconazole shampoo twice a week and oral itraconazole 100 mg once daily along with trimming of the hair regularly, resulting in a decrease in the palpability of nodules (concretions) and fragility of scalp hairs at the end of 2 months, with complete resolution at the end of 3 months. The patient was followed for the next 6 months, during which time there was no relapse.

DISCUSSION

White piedra belongs to family Cryptococcaceae, class Basidiomycetes and is an unusual infection of worldwide distribution usually seen in temperate and topical areas including Europe, Asia, Japan, and southern United States.[12]

It is caused by a T. beigelii, now known as Trichosporon asahii,[3] yeast-like fungus, first described by Beigel in 1865 and the first case in India was reported by Basu et al. in 1970.[2]

All age groups are affected, with a higher incidence in young women.[4] Age and sex incidence varies from country to country, depending on the prevalent hairdressing fashions and social customs.[2] Whether the custom of covering hairs is a contributory factor that needs to be studied. The higher incidence of scalp white piedra is observed in Muslim females; contributing factor being the custom of using a veil, leading to higher humidity, and limited sunlight exposure. Only a handful of cases of white piedra have been reported in the past [Table 1].

Table 1

Various reported cases of white piedra

Author	Age (years)	Gender	Clinical presentation	Species	Treatment given
Our case		Female
Khandpur S et al., 2002	12 patients	Female			Itraconazole
Anupama S Roshan et al., 2009	45 years 20 years	Female	Whitish to cream-colored, easily detachable nodules of size 1-1.5 mm present over the shaft of almost all the scalp hairs		Topical application of 1 in 2000 mercuric perchloride for 3 months, trimming of the hair, topical terbinafine (1%) twice daily for 3 months
Swapna S Khatu et al., 2013	40 years	Female	Mixed white and black piedra with pediculosis capitis		Trimming of her hair and application of 2% ketoconazole lotion
Tambe SA et al., 2009			Brown palpable nodules along the hair shaft with a fragility of scalp hairs		Oral itraconazole and topical ketoconazole
Viswanath V 2011	50 years	Female	White knots over scalp hair	T. inkin	Topical antifungals
Zaror L et al., 1996	18 years	Male	White-yellowish nodules of 1 mm diameter, agglutinated or forming chains, even forming threads		Topical antifungals
Anita Vijay et al., 2017	30 years	Female	Coinfection with white piedra and pediculosis capitis		Oral itraconazole 100 mg per day
Uma Tendolkar et al., 2014	20 years	Male	T. mucoides was identified by a positive growth at 37°C and sorbitol assimilation test and T. inkin was identified by a positive growth at 37°C, inositol assimilation and appressoria formation and a negative sorbitol assimilation test	T. inkin in 2 patients and T. mucoides	Cutting of hair and 2% selenium sulfide shampoo wash on alternate days. Oral itraconazole 100 mg
	7 years	Female
	35 years	Female

T. mucoides: Trichosporon mucoides, T. inkin: Trichosporon inkin, T. inkin: Trichosporon inkin

Gueho has subdivided T. beigelii into six species, pathogenic to humans.[25] These include Trichosporon ovoides, Trichosporon inkin, Trichosporon ashii, Trichosporon mucoides, Trichosporon asteroides, and Trichosporon cutaneum. Carbohydrate assimilation test is done for species identification. T. ovoides and T. inkin are usually associated with white piedra. T. ovoides causes white piedra of the scalp, while T. inkin leads to pubic piedra. T. asteroides and T. cutaneum are isolated less frequently in superficial lesions and are probably contaminants.[2] T. ashii causes hematogenously disseminated infections, while T. mucoides usually causes central nervous system involvement in immunocompromised patients. Therefore, species identification is an important aspect.

The differential diagnosis includes pediculosis capitis, trichomycosis axillaris (trichobacteriosis), monilethrix, trichorrhexis nodosa, and peripilar keratin cast [Table 2].[2] Shaving of affected hair is the most effective and curative remedy but generally not acceptable in females.[1] Topical antifungals commonly used are 2% ketoconazole, ciclopirox olamine shampoo, 2% selenium sulfide, 6% precipitated sulfur in petrolatum, zinc pyrithione and amphotericin B lotion, or 1% terbinafine four times a day for 2 weeks or till remissions occurs.[3] Oral agents include ketoconazole and amphotericin B.[6] Recent reports show that itraconazole is also effective in the treatment of white piedra, although it relapses frequently.[4] Therefore, oral azole antifungal agents eliminate the scalp carriage or infection, whereas topical antifungal eliminates the hair shaft concretions without the need for shaving.[5]

Table 2

Differential diagnosis of white piedra

Disease	White Piedra	Black piedra	Pediculosis capitis	Trichomycosis axillaris	Monilethrix	Trichorrhexis nodosa
Etiology	Trichosporon sp.	P. hortae	P. humanus var. capitis	C. flavescens	Disorder of hair shaft with increased fragility	Hair shaft disorder due to repeated trivial trauma
Clinical presentation	Soft, whitish nodules attached to the hair cuticle	Black-colored, firm, irregular nodules, located in the hair cuticle	Itching of the scalp	1-2 mm discrete nodules attached to axillary hair shafts	Beaded appearance due to alternate zones of spindle-like thickening and thinning placed about 0.7-1 mm apart	Firmly attached, white nodular thickening on the distal part of the hair shaft
Associated findings			Secondary bacterial infection with impetiginization with cervical and occipital lymphadenopathy	Axillary hyperhidrosis and bromhidrosis, stained clothes, and roughened texture of axillary hair	On occiput and nape of the neck, keratotic follicular papules	Trichoclasis
Investigation	Growth on Sabouraud agar Lactophenol cotton blue mount		Presence of nits within 7 mm of the scalp indicates an active louse infestationNoncontact dermoscopy	10% KOH shows pods or concretions, which are actually masses of bacteria surrounding the hair shaft  Microscopic visualization of 0.5-1 µm coccoids and diphtheroids adherent to hair shaftsWood’s lamp examination shows fluorescence		Light microscopy showed fraying of cortical fibers giving the appearance of two paint brushes thrust together

P. humanus – Pediculus humanus; C. flavescens – Corynebacterium flavescens; P. hortae – Piedraia hortae; KOH – Potassium hydroxide

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

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Conflicts of interest

There are no conflicts of interest.