Thermoregulatory Disorder

The normal body temperature of a child depends on several factors (age, measurement method, time of day, activity level, etc.). On average, the normal rectal temperature ranges between 36.6 and 37.4 °C. 

A temperature above 37.5 °C is called elevated temperature, between 38.1 °C and 38.5 °C mild fever, and from 38.6 °C fever. 

The point at which a patient begins to feel subjectively ill or unwell varies from person to person.

Fever often is a defense reaction of the body, for example against pathogens such as viruses or bacteria. Fever can also occur in the context of autoimmune or tumor diseases. A special form is so-called central fever. In this case, the fever is caused by a disturbance of the brain’s temperature center. Antipyretic medications are often ineffective against central fever.

The Situation With PCH2 Children

Thermoregulatory disorder in the form of hypothermia (abnormally low temperature) or hyperthermia (abnormally high temperature) without an identifiable infectious cause has been reported repeatedly in children with PCH2. Hyperthermia, i.e. fever without a clear cause, is described more frequently. The literature includes reports of fatal outcomes associated with hyperthermic crises in PCH2. 

Additionally, many children with PCH2 exhibit a rapid rise in temperature during infectious episodes, often accompanied by agitation and crying. This agitation may occur even before a detectable rise in temperature. Consequently, many parents recommend monitoring body temperature whenever increased restlessness is observed. 

Therapy

Antipyretic medications (e.g. ibuprofen, paracetamol) do not consistently reduce body temperature, but – potentially in combination with antiepileptic medications – may help alleviate agitation. Physical cooling methods (cool baths, cooling compresses) frequently prove effective in reducing fever.

Tips to Try Out

• Regularly monitor body temperature when unexplained or increased restlessness/discomfort is observed.
• In case of elevated temperature, use physical cooling methods such as a cool bath (preferably lukewarm, not too cold) or cooling compresses; keep taking the temperature frequently.
• Ensure sufficient fluid intake.
• Administer antipyretics early in consultation with the child’s physician.
•  Talk to a physician early when the response to these measures is inadequate or if unsure.

Scientific Background

Data From The Literature

• Barth et al. (1990) reported two children who died during hyperthermic crises with temperatures up to 41 °C accompanied by severe dyskinesia.
• Uhl et al. (1998) described a child who died at 2.5 years of age during a hyperthermic crisis associated with severe chorea.
• Barth et al. (2008) reported severe hyperthermia with concurrent rhabdomyolysis in two cases.

Natural History Study from 2014

Thermoregulatory disorders (mostly without identifiable causes such as infection) were observed in 22 of 33 children. n 2 cases these manifested as hypothermia (too low); the remainder presented with hyperthermia (too high). One child developed rhabdomyolysis (dissolution of muscle fibers).

Natural History Study from 2023

38 of 65 children had thermoregulatory disorders from a mean age of 2 years. 28 presented with fever of unknown cause, 11 with low body temperature, and 3 with rapid unexplained temperature spikes. In 3 children, symptoms resolved over time. 

Paracetamol or ibuprofen was administered for fever; one child showed a paradoxical temperature increase with both agents. In one case, it was reported that standard antipyretics were ineffective against fever without identifiable cause.

This entry was written to the best of our knowledge based on the reported experiences of parents of affected children. In addition, currently available data from the 2014 and 2023 Natural History Studies of PCH2 and from general medical literature has been included. It is not a substitute for consulting a medical professional. PCH2cure assumes no liability in this respect.