**4. Other human diseases associated to chiggers**

Apart from trombiculiasis, chiggers are responsible for other less frequent conditions. The summer penile syndrome is a seasonal acute hypersensitivity reaction attributed to chigger bites [114,115]. It occurs in young boys with a history of bites or outdoor exposure, and it is characterized by the rapid onset of edema and pruritus of the penile skin. It has been described most commonly in the spring and summer in different regions of United States [114,115]. Another example is the unique case of conjunctivitis induced by *N. autumnalis*, reported in United Kingdom [109]. The patient had a 2-week history of a painful, gritty, red left eye, which failed to improve with a liquid paraffin eye ointment. On examination, her conjunctiva was found to be mildly red and she had normal visual acuity. On close inspection, a live mite was identified in contact with the left upper eyelid margin.
