pilonidal sinus is a well recognized chronic inflammatory condition which affects the natal cleft , finger web space , and it is rare in the penis
. we report on a case of penile pilonidal sinus in a 24-year - old man who has severe mental illness , autism , and developmental delay .
the literature was reviewed and there were a few cases reported worldwide ( val - bernal et al 1999 ; chikkamuniyappa et al 2004 ; kalsi et al 2004 ; okane et al 2004 ) .
a 24-year - old man who is known to have severe mental illness , autism , and a learning disability , presented with more than a one year history of recurrent ulcerative lesion on the middle of the dorsum of his penile shaft , intermittent erythema , and swelling . despite several courses of antibiotics prescribed by his local general practitioner
, the lesion did not resolve and the swelling was observed to grow bigger between these episodes .
clinical examination revealed an indurated , erythematous 89 mm ulcerative lesion in the middle of the dorsal aspect of the penile shaft .
the patient had not been circumcised and had never reported a similar complaint from anywhere else in his body .
excisional biopsy was performed , and histology showed the classical findings of pilonidal sinus with hair shaft within .
it is essential to highlight the fact that diagnosis was made post - operatively based on histopathological findings rather than on preoperative clinical assessment . in some cases diagnosis
pilonidal sinus was first described by anderson ( 1847 ) . it is a condition that affects hairy areas such as the natal cleft , axillae , perineum , finger web space in the hands of barbers , and amputation stumps ( saharay et al 1997 ) .
the pathogenesis of pilonidal sinus is controversial although it is agreed that it is acquired .
the present view is that the large majority of pilonidal sinuses have an acquired pathogenesis .
the initiating event appears to be follicular hyperkeratosis with plugging , leading to retention of follicular products ( lucas 1997 ) .
the rupture of a follicular unit or a cyst with secondary infection results in abscess formation . in some instances , sinuses formed to drain the abundant suppuration .
the sinuses are lined by stratified squamous epithelium and inflammatory granulation tissue . very often ,
numerous hair shafts penetrate into dermis and elicit foreign body giant cell reaction ( figure 13 ) .
the support for the acquired theory of the pilonidal sinus comes from their occurrence in situations such as the finger web space in the hands of barbers , and in amputation stumps . therefore many cases are acquired as a result of trauma from 
jeep seat  ,  rough riding syndrome  , and occupational physical injury ( val - bernal et al 1999 ) .
the literature was reviewed and a few cases were reported worldwide ( val - bernal et al 1999 ; chikkamuniyappa et al 2004 ; kalsi et al 2004 ; okane et al 2004 ) .
the literature referred to penile pilonidal sinus with some other pathologies such as actinomycosis infection ( val - bernal et al 1999 ; chikkamuniyappa et al 2004 ) or erectile dysfunction ( kalsi et al 2004 ) .
therefore , a good clinical assessment and bacteriological examination is essential to obtain better results . in our case
, we reported on a pilonidal sinus where diagnosis was made on histopathological findings with no evidence of associated bacterial infection or malignancy ( rao et al 2006 ) .
our patient had full recovery and no symptoms since , his post - operative follow - up involved two out - patient visits at up to 12 weeks post - operation .
the patient had no symptoms or recurrence up to that time , interval circumcision was deferred due to the patient s general health status and his mental disability .
 pilonidal sinus is a well recognised chronic inflammatory condition which commonly affects the natal cleft and finger web space . 
 pilonidal sinus of the penis is a rare clinical entity ; few cases have been reported previously . 
 the treatment strategy is almost the same as treating any pilonidal sinus and involves total excision of the sinus . 
 our diagnosis was established on the histopathological findings rather than a clinical - based diagnosis , follow - up is advisable since the recurrence rate is high . 
 our case report is one of few cases reported on pilonidal sinus all over the world . 
 our patient had total excision of the sinus with complete recovery . 
Introduction
Case report
Discussion