Case report on an unusual condition

Five days ago, a 9-year-old male patient was referred to our hospital from a local dispensary with suspect of paraphymosis.

On first examination we have realized that the provisional diagnosis was not correct: in fact the prepuce was present and not retracted, although the glans penis was severely oedematous and painful. The skin itself was swollen and inflamed up to the base of the shaft, while scrotum and perineum were not involved in the inflammatory process. There was no reactive lymphadenopathy at the groin.

We suspected an insect or spider bite, with inflammation and infection of the affected area, although we had not been able to detect any site of possible biting or sting. Actually there were no wounds at all on the penis.

We have therefore started treatment with broad spectrum antibiotics (Penicilline G and Gentamycine) and we have also added a short course of steroids (Hydrocortison 50 mg TID for 3 days), in order to reduce the oedema quickly.

We have also inserted a folley catheter (gauge 6 Ch), because the oedema was making the micturition difficult. We have not given any boost of Tetanous Toxoid because the child was fully vaccinated.

The improvement has been quick and impressive, with steady reduction of the oedema and disappearance of pain.

We have therefore removed the indwelling catheter 2 days after insertion, and the child did not complain of any problem in passing urine.

Yesterday only a small area at the tip of the glans penis was still swollen and we were planning for discharge.

Nevertheless, a few hours later the mother of the patient called us because something whitish had appeared on the skin surface of the area still swollen on the prepuce.

Using a magnifying lens I have realized that it was part of a viable larva, moving about and trying to emerge.

With the help of a very mild sedation (a small dose of ketamine), we have gently squeezed the area, recovering the big larva shown in the pictures: the larva was viable and mobile.

We have carefully examined the skin around and we believe there was no other larva.

The latter accident has given us a definitive diagnosis: it was not an insect or arachnid sting, but a case of myiasis (maggot).

The absence of a chronic ulcer at the affected area makes us think of foruncular myiasis.

We will keep the child under observation for few days, in order to complete the course of antibiotics and to insure proper hygiene of the area, including the glans penis, after gentle retraction of the prepuce.

We have also decided to give a single dose of oral ivermectin, in order to target other possible larvae which may have escaped our observation. 

CONCLUSION

Myiasis is still a common dermatological condition in our area, and we must always think of it. Foruncular myiasis prefers the parts of the body covered with clothes and above all the areas around the genitals because the fly is attracted by the smell of urine. It is also more common in young children than in adults. Differently from the cases of wound myiasis, sometimes the diagnosis of foruncular myiasis is very difficult, above all when you cannot see a punctum (site of entry) at the centre of the affected area. Local lymphadenopathy is not common. Finding the larva is the only definitive diagnostic tool, while hygiene is paramount in order to prevent relapse.

Dr Giuseppe Gaido