International Journal of Trichology

LETTER TO EDITOR
Year
: 2012  |  Volume : 4  |  Issue : 1  |  Page : 51--52

Giant congenital triangular alopecia mimicking alopecia areata


Chandramohan Kudligi, Pradeep Vittal Bhagwat, Mohan Shendre Eshwarrao, Neha Tandon 
 Department of Skin and STD, Karnataka Institute of Medical Sciences, Hubli, Karnataka, India

Correspondence Address:
Chandramohan Kudligi
Department of Skin and STD, Karnataka Institute of Medical Sciences, Hubli, Karnataka
India




How to cite this article:
Kudligi C, Bhagwat PV, Eshwarrao MS, Tandon N. Giant congenital triangular alopecia mimicking alopecia areata.Int J Trichol 2012;4:51-52


How to cite this URL:
Kudligi C, Bhagwat PV, Eshwarrao MS, Tandon N. Giant congenital triangular alopecia mimicking alopecia areata. Int J Trichol [serial online] 2012 [cited 2019 Dec 7 ];4:51-52
Available from: http://www.ijtrichology.com/text.asp?2012/4/1/51/96102


Full Text

Sir,

A three-year-old boy was brought to us by his parents for the evaluation of localized hair loss over the left fronto-temporo-parietal region. The area of alopecia was noticed at the age of one year. Since then, there was no increase in area or change in the appearance of hairless patch. Patient was treated with twice daily local application of mometasone furoate 1% lotion for a period of six months without any significant improvement. Parents did not remember any history of trauma, redness, swelling, erosion or ulcer prior to the onset of hair loss. They also denied seeing any hair pulling or manipulation of the hairless patch. None of the family members had similar complaints. General physical examination was unremarkable. On cutaneous examination, there was a fairly well-demarcated, triangular shaped, non scarring alopecia occupying two third of left temporoparietal region. The base of the triangle extended from left frontal prominence to a point 2.5 cm above the left tragus. The apex of the triangle was 2.5 cm lateral to the vertex [Figure 1]. Fine vellus hairs were present in the bald area and there was no erythema, induration, scaling or scarring in the lesion. Hair pull test was negative. Exclamation mark hairs were absent. Examination of nails did not show ridging or pitting. Parents did not give the consent for the skin biopsy. Based on the characteristic history and cutaneous examination, the diagnosis of congenital triangular alopecia was made.{Figure 1}

 Discussion



Congenital triangular alopecia (CTA), also named temporal triangular alopecia, was first described by Sabouraud in 1905. [1] It is a developmental defect characterized by a unilateral or, more rarely, bilateral bald patch involving the temporal region in a triangular or oval shape. [2] This condition, once considered congenital, is acquired in the majority of cases. Most patients present between three and six years of age. [3] The cause of CTA is so far unknown. It has been argued that CTA may reflect mosaicism and may be transmitted as a paradominant trait. [4] CTA usually occurs as an isolated anomaly, but it may also be a part of multisystem birth defects such as cerebellar-trigeminal-dermal dysplasia (Gómez-López-Hernández-, GLH, syndrome) or phacomatosis cesioflammea (phacomatosis pigmentovascularis type II). [5] CTA is not a rare disease. The seeming rarity appears to be due to its ability to go unrecognized because it is asymptomatic, nonprogressive, blends with the hair line and also might be due to its smaller size. [6] But rarely CTA involves large temporoparietal region. Such giant CTA represents characteristic feature of GLH syndrome, a complex birth defect including craniosynostosis, midfacial hypoplasia, trigeminal anesthesia, cerebellar dysplasia and mental deficiency. [5] Though our patient had similar wide spread triangular alopecia, detailed examination did not reveal any features suggestive of GLH. The diagnosis of congenital triangular alopecia commonly is made based on clinical features and distribution and not on biopsy results. [3] However, microscopic examinations show miniaturized hair follicles, differentiated sebaceous glands and lack of inflammatory infiltrate. Though CTA has been confused with alopecia areata, many features like stable course, triangular shape, poor response to topical steroids and lack of exclamation mark hair help in diagnosing CTA and ruling out alopecia areata. Other conditions that should be considered under differential diagnosis are trichotillomania, tinea capitis, androgenetic alopecia and aplasia cutis. All these conditions can easily be ruled out by proper history and careful clinical examination. The only known successful treatment for this condition is complete excision of the affected area or hair graft transplantation. [7] The present case is being reported for two reasons. 1) To draw attention to the fact that CTA involving large temporoparietal region is not always associated with GLH syndrome but can appear as an isolated bald patch. Future research may be required to know whether isolated giant CTA is a separate entity or an incomplete form of GLH syndrome. 2) To familiarize the clinicians about the unusual presentation of this condition which helps in proper diagnosis and prevents inadvertent use of corticosteroids.

References

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