Cellulitis of the penis: a case report

Abstract

Cellulitis of the penis is an uncommon clinical condition, most often seen in young men, and presents with local and systemic signs that progress rapidly in the absence of treatment. It needs to be differentiated from sexually transmitted infections and dermatological conditions. The present report concerns a case of penile cellulitis in a young, heterosexual man, following sexual intercourse. The clinical presentation, aetiology and management are discussed. Penile swelling in any age group should be viewed with high index of suspicion and sexually transmitted infections should be excluded in young men. Group B haemolytic streptococci are the usual causative organisms, although less virulent organisms should be considered in patients who are immunocompromised. Administration of appropriate antibiotics resolves the local and systemic symptoms and avoids complications.

BACKGROUND

Cellulitis of the penis is an uncommon condition, seen infrequently as an acute case in urology.

CASE PRESENTATION

We present the case of a 35-year-old man with a 4-day history of throbbing penile pain and gradually worsening swelling, following sexual activity. The pain became unbearable and had some dysuria and urinary frequency, but no urethral discharge. Since the onset of symptoms, the patient had not had any erections and any slight movement made the pain worse. There was no history of diabetes mellitus and the patient was not taking any regular medications.

On the day of presentation to the Emergency Department he had a temperature of 39°C and there was an enlarged right inguinal lymph node that measured about 1 cm. The abdomen was non-tender and soft. The penis was grossly enlarged, swollen and oedematous, and the skin was erythematous. No vesicles or pustules were seen and there was no discharge. It was extremely tender and it was impossible to retract the prepuce, hence the external meatus could not be seen. However, the distal part of the penis, especially over the corona, appeared fuller and was the point of maximum tenderness. Both corpora were quite firm, but non-tender and soft at the penile base and there was no fluctuation. While still in the Emergency Department, the patient noticed some foul-smelling purulent discharge that was sent for culture.

INVESTIGATIONS

A complete blood count revealed white cell count of 16.3×10⁹/litre with neutrophilia of 13.5×10⁹/litre; urea and electrolytes were normal.

TREATMENT

Intravenous broad-spectrum penicillin was given initially for the first 24 h and this was later switched to oral administration. The patient responded to this regime very well; the pain and swelling were reduced in the first 24 h. With culture results pending and the rapid response to antibiotics, the patient was discharged with a further 2-week course of oral antibiotics, with a follow-up date. Streptococcus milleri was isolated from the purulent fluid after extended incubation and was sensitive to penicillin.

OUTCOME AND FOLLOW-UP

The patient recovered very well after the course of antibiotics.

DISCUSSION

Penile cellulitis is uncommon and predominantly seen in sexually active young men. However it affects all age groups and has been reported in newborns¹ and young children.² The mode of transmission in the newborn and very young is from the surrounding infective foci, either from the perineum or scrotum. Breach in the Buck fascia due to perianal surgery could sometimes lead to the spread of an infection to the penis and scrotum clinically presenting as cellulitis. In teenagers who are not sexually active congenital lymphangioma leads to recurrent bouts of penile cellulitis in the absence of trauma.² Venereal penile oedema is penile swelling after vigorous sexual activity, and may represent a low-grade cellulitis.³ Cellulitis of the penis can spread as a sexually transmitted infection, especially in uncircumcised men.⁴ It may be acquired through oral sex.⁵

Streptococci are the most common causative organisms isolated, especially β-haemolytic group B streptococci.⁶ Group B haemolytic streptococci are known to colonise the throat and lower female genital tract; prevalence is 4% to 18%.⁶ Other causative organisms include Staphylococcus, Chlamydia trachomatis, Escherichia coli, Klebsiella pneumoniae, Bacteroides spp. and anaerobic streptococci. Fournier gangrene has been reported to exclusively involve the penile skin, sparing the scrotum.⁷ Candida can sometimes cause infection leading to cellulitis and abscess formation, especially in poorly controlled diabetics and debilitated individuals.⁸ Other host factors such as alcoholism, trauma (including surgery), intracavernosal injection for erectile dysfunction penile prosthesis and immunosuppression may predispose a patient to penile cellulitis. Congenital⁹ or acquired lymphangioma should be considered as a cause of recurrent penile cellulitis, particularly in young men who are not sexually active.

Cellulitis of the penis usually presents with penile swelling and pain, and may be associated with discharge. Urinary symptoms, systemic toxicity and inguinal lymphadenopathy may be noted. Sexually transmitted infection should be ruled out and purulent discharge, if present, sent for Gram staining and culture. In our patient, broad-spectrum penicillin (erythromycin, if allergic to penicillin) was commenced and progress monitored. There is usually a rapid response and most cases resolve with antibiotic therapy. Antibiotics need to be changed when culture reports are available. If there is no response to antibiotic treatment, an alternate diagnosis should be considered. A penile ultrasound scan can help in excluding deep-seated abscess and may aid in guided aspiration/drainage. Surgical debridement and superficial skin grafting may become necessary in cases of extensive skin necrosis. It is wise to send the skin for histology as it may harbour an unsuspected squamous cell carcinoma.⁷

Balanitis involving the prepuce, especially those due to Streptococcus, may present with signs of inflammation and purulent discharge. Allergic conditions may present with boggy penile swelling and erythaema.¹⁰ Allergic contact dermatitis clinically presents as oedema and erythaema of the penile skin due to sensitisation. Similarly, men with a latex allergy may have oedematous penis with eruptions. In both these conditions, systemic signs are conspicuously absent and symptoms respond to either local or systemic steroids.

Penile swelling in any age group should be viewed with a high index of suspicion and sexually transmitted infections should be excluded in young men. β-Haemolytic Streptococcus is the most common organism, and the possibility of other causative organisms should be considered in cases of patients who are immunosuppressed and patients who are diabetic. Abscess should be excluded by imaging studies. Early treatment with broad-spectrum antibiotics prevents local and systemic complications. In cases of cellulitis due to lymphangioma, surgical resection of the involved skin with grafting helps. Long-term prophylactic antibiotics may be considered in those unwilling to undergo surgery, as the response to antibiotics is remarkable in majority of cases.

LEARNING POINTS

• Cellulitis of the penis is an uncommon clinical condition seen in sexually active, uncircumcised men.

• A high index of suspicion is required in clinical diagnosis with symptoms of penile swelling.

• Aggressive antibiotic treatment prevents complications.

• Penile cellulitis can be acquired sexually.