Stevens-Johnson Syndrome Associated with Codeine in a Child

Abstract

Stevens-Johnson syndrome and toxic epidermal necrolysis (TEN) are part of a spectrum of mucocutaneous disorders with similar clinical features. The incidence of TEN and StevensJohnson syndrome has been estimated at 0.4 to 1.2 and 1 to 6 cases per million person-years, respectively.[1-3] Factors such as race, age, gender and socioeconomic status do not appear to affect the epidemiology of the two disorders. The pathophysiology of these skin syndromes remains unknown. Stevens-Johnson syndrome is considered to be a milder form of TEN. StevensJohnson syndrome typically presents as small blisters on dusky pruritic macules on the face and upper trunk, occurring 1 to 3 weeks after drug exposure. The rash progresses rapidly to include the epithelium of the gastrointestinal and respiratory tracts and eyes, and it usually reaches its maximum within hours to days.[4] Detachment of less than 10% of the epidermis is considered StevensJohnson syndrome, while involvement of greater than 30% of the body surface is diagnosed as TEN. Fever is usually higher in TEN than in StevensJohnson syndrome. Mortality depends upon the extent of skin necrosis and damage to other systems and is usually below 5% for Stevens-Johnson syndrome and as high as 30% in cases of TEN.[1,5] Patients may be severely dehydrated with electrolyte abnormalities, and anaemia, lymphopenia and pre-renal azotemia are common. Bacterial colonisation of the skin and decreased immune response increases the likelihood of sepsis, the major cause of death.[4] Thirty-five percent of patients with TEN and fewer with Stevens-Johnson syndrome experience ocular sequelae including formation of synechiae between the eyelids and the conjunctiva, corneal erosions and scarring, and punctate keratitis.[6] Neutropenia, visceral involvement and high blood urea nitrogen levels are associated with a poorer prognosis. While both are primarily associated with drug use, infections, including mycoplasma pneumonia and viruses, are also implicated in the Stevens-Johnson syndrome. The drugs most often causing Stevens-Johnson syndrome and TEN include sulfonamides, aminopenicillins, phenytoin and nonsteroidal anti-inflammatory drugs (NSAIDs). Despite its wide clinical use for cough suppression and pain control, codeine has not been implicated as a cause of Stevens-Johnson syndrome. We report a paediatric case of Stevens-Johnson syndrome associated with codeine phosphate.