Contributors: Emeritus Professor John Goldsmid, University of Tasmania
Patient 1: This patient had been walking barefoot while trekking in the Amazon River basin in Brazil. She noted a series of small itchy papular lesions between her toes (Fig.8.1) which lasted a few days and then gradually healed.
Patient 2: This patient had been on honeymoon to a seaside resort in Malaysia where she had been walking barefoot on the beach. Shortly after her return home to Tasmania, she noticed an itchy sinuous tunnel-like rash on her foot (Fig.8.2). This persisted for several weeks, extending in length day by day.
Patient 3: This patient was a 65 year old Tasmanian admitted to hospital for surgery for cancer. The anaesthetist noted, in a preoperative examination, that the patient had a sinuous, tunnel-like rash on his buttocks (Fig.3). The patient explained that he had suffered from these rashes ever since he had been discharged from the army some 40 years previously. He had been a prisoner of war of the Japanese in World War II and had worked on the Burma-Thailand Railway. Initially the rashes had been very sporadic, but in recent years they had appeared more frequently. The rash lasted about a week and then disappeared. He had initially consulted a GP who had referred him to a dermatologist. The latter had been unable to diagnose the problem and referred him to a psychiatrist who diagnosed it as a “psychosomatic rash” and it had been managed as such for the last 10 years.
Patient 4: This patient was a young nurse who presented to her doctor in Hobart with an itchy punctate rash on her legs below the knees (Fig.4). On being questioned, she said that she had just returned to Tasmania after a recent holiday in New South Wales during which she had been wading in the sea netting for prawns. The rash corresponded in distribution with the parts of her body that had been immersed in water and had appeared a few hours after exposure to the sea water but was now getting better.
What is your diagnosis?
Patient 1: This patient has “ground itch” – also known as “dew itch”. It may be caused by the filariform larvae of hookworms which may infect human hookworms, Ancylostoma duodenale; Ancylostoma ceylanicum and Necator americanus as they penetrate the skin. Treatment is symptomatic to relieve the itching. It might also be prudent to treat for hookworm with albendazole or at least to check the patient after a period of about 6 weeks for hookworm infection
This patient has cutaneous larva migrans – also known as “sandworm” or “creeping eruption”. It is caused when infective larvae of dog or cat hookworms (Ancylostoma braziliense; A. caninum; Uncinaria stenocephala penetrate the human skin and wander around in the skin for periods of up to 2 months. The condition can also more rarely be caused by the cattle hookworm (Bunostomum phlebotomum) and the maggot of the intestinal botfly, Gastrophilus sp.
This patient has a larva currens rash resulting from autoinfection with the larvae of Strongyloides stercoralis. In this case the patient was initially infected while a POW in SE Asia. The infection persisted on his return home due to autoinfection, with the infective larvae of the worms reinfecting him through a process of internal and external autoinfection. Larvae had been passing out through the anus and then burrowing in through the skin of the buttocks, thus giving rise to the periodic tunnel-like, sinuous rash lasting a week or so before subsiding as the larvae passed through the skin into the circulatory system, eventually to develop into more adult worms and so maintain the infection. The rashes had increased in recent years probably due to the aging process, the patient’s cancer together with a decline in the efficiency of the patient’s immune system. If such patients are given radiation or other immunosuppressive treatment, a fatal autoinfection with the Strongyloides can result. Diagnosis can be confirmed by repeat stool examination, use of the duodenal capsule or “string test”, by Harada Mori Test Tube Culture or by serology.
This patient has cercarial dermatitis, caused by the penetration of the skin by schistosome cercariae. In areas endemic for human schistosomiasis, this condition can be caused during the infection process and eggs can be detected in stool or urine some 6 weeks later (the prepatent period). In temperate regions and areas in which there is no human schistosomiasis, the cercarial dermatitis can result from the attempted penetration of the human skin by schistosomes of animals (particularly those of water birds) and the condition is known in Australia as “pelican itch” and elsewhere as “swimmer’s itch” Diagnosis is based upon clinical examination and a history of exposure. Treatment of swimmer’s itch is symptomatic to relieve the itching. If the patient was infected in a schistosome endemic area and subsequent examination revealed eggs of Schistosoma haematobium, S. mansoni or S. japonicum or if schistosome antibody serology is positive.
Bartlett, J.G. (2002) Pocket Book of Infectious Disease Therapy. Lippincott Williams and Wilkins. Philadelphia.
Sheorey, H., Walker, J., and Biggs, B-A (2000). Clinical Parasitology. Melbourne University press. Melbourne.