Gianotti-Crosti Syndrome

Gianotti-Crosti syndrome, also known as papular acrodermatitis of childhood, is a self-limited skin condition characterized by a papulovesicular rash on the skin of the buttocks, legs, and arms. It usually appears after a viral infection and most commonly affects children around the ages of one to three years of age. 

The underlying mechanism of Gianotti-Crosti syndrome is currently unknown; however, it is thought to be caused by a delayed hypersensitivity reaction to viral infections. In the United States, the most common cause is Epstein-Barr virus (EBV) infection, which is responsible for most cases of infectious mononucleosis, otherwise known as the “kissing disease.” In countries where vaccination against hepatitis B is not as widespread, hepatitis B virus infection is a common cause of Gianotti-Crosti syndrome. Other viruses that can cause the rash include hepatitis A and C; enteroviruses, like coxsackievirus and rotavirus; and many respiratory viruses, such as respiratory syncytial virus (RSV) and parainfluenza, among others. 

Less commonly, Gianotti-Crosti syndrome has been reported following vaccination with certain viral vaccines, including influenza, measles-mumps-rubella (MMR), and hepatitis A and B. However, the mechanisms as to why these reactions occur still remain unclear. Finally, there have been a few cases associated with infection with the human immunodeficiency virus (HIV) and bacterial infections. 

Like most other viral rashes, Gianotti-Crosti syndrome typically affects children of preschool age, although it has occasionally been reported in teenagers and adults. The rash is more common in the spring and summer months and occurs more frequently in children with atopic dermatitis (i.e., eczema).

Gianotti-Crosti syndrome causes a self-limited rash that can last anywhere from 10 days to six months. Lesions consist of single, pink to red-brown papules that may be fluid-filled and are generally not itchy. The rash usually begins on the thighs and buttocks and then spreads to the arms and face. In addition to the rash, children may present with flu-like symptoms, such as low-grade fever and enlarged lymph nodes. An enlarged spleen or liver may also be seen when certain viral infections, such as with hepatitis B virus or Epstein-Barr virus, are the underlying cause.

Gianotti-Crosti syndrome is diagnosed clinically in children with a compatible rash that develops after an upper respiratory infection, gastroenteritis, or another viral infection. Laboratory tests are generally not necessary to confirm the diagnosis but may sometimes be performed to identify the underlying cause, especially in children that may benefit from close monitoring or specific treatment. A skin biopsy is also not useful to confirm the diagnosis; however, it may be used to rule out other skin conditions if the diagnosis is unclear.

There is no specific treatment for Gianotti-Crosti syndrome as the rash typically fades away on its own over four to eight weeks. During this time, treatment is mainly supportive and can include cool baths, emollients, or calamine lotions to help reduce itching, if present. Treatment can also include anti-inflammatory medications to reduce associated constitutional symptoms. Low-potency topical corticosteroids are also sometimes administered; however, they haven’t been shown to reduce the duration of the symptoms. Finally, oral antihistamines may be administered if lesions are very itchy and they interfere with sleep or other activities.

Gianotti-Crosti syndrome is a self-limiting viral skin rash that typically affects children under the age of five years. The rash consists of pink-brown, flat-topped papulovesicular lesions on the face, arms, and legs and is usually preceded by symptoms of a viral infection, like a sore throat, rhinitis, or gastroenteritis. Diagnosis is clinical and treatment is mainly supportive as skin lesions typically resolve on their own over the course of a few weeks.