Sickle cell disease (SCD) is a condition that is caused by a mutation in beta- globin gene of the hemoglobin tetramere. This mutation results in a substitution of a valine residue for a glutamic acid residue, resulting in sickle hemoglobin (HgS). When HgS is deoxygenated it undergoes aggregation and polymerization, leading to damage of the red blood cell membrane. Damaged red cell membrane allows abnormal accumulation of calcium in the cell, which activates potassium ion channels, leading to efflux of potassium and water. This intracellular dehydration plays a very important role in pathogenesis of microvascular occlusion. Sickle cell crisis is most commonly precipitated by processes that subsequently lead to dehydration, such as infection, vigorous exercise, or exposure to temperature extremes. Sun tanning is known to cause damage to the skin, causing an inflammatory response. This ultimately increases oxygen demand, potentially leading to increased red blood cell sickling.
An 18-year-old Middle Eastern woman with past medical history of only sickle cell disease, presented the emergency department (ED) with the chief complaint of altered mental status (AMS). In the ED patient was found to be hypoxemic with an oxygen saturation of 59%. She was admitted to the ICU for further diagnostic work up and management. The patient reported having two sun tanning sessions over the past two days and subsequently experienced diffuse body pain the night of the second session. Signs and symptoms altered mental status followed that morning. She reported no history of vigorous exercise, alcohol or illicit drug use, history of significant stress, high altitude, exposure to extremes of temperature. On physical examination, the patient appeared to be in moderate distress, reporting pain in her left shoulder and both lower extremities. Her pulse initially was 144 beats/min, respiratory rate of 20, temperature of 40.2 C, oxygen saturation ranged from 95–97 on 3L nasal cannula. Patient was alert and oriented to self, place, and time. She had increased pallor, the physical exam was otherwise unremarkable. A chest radiograph showed no abnormalities. Electrocardiogram revealed sinus tachycardia as the only abnormality. Infectious workup was negative and included blood and urine cultures. Patient’s hemoglobin was initially 6.9 g/dl and decreased to 5.2g/dL, with other hematological studies consistent with acute hemolysis. Over the next three days patient was rehydrated and received one unit of packed red blood cells. She was discharged on the fourth day after her hypoxemia resolved and hemoglobin stabilized. No permanent sequeale from this sickle cell crisis were identified.
SCD results from a mutation in the DNA that leads to substitution of one amino acid for another. The acute sickle cell crisis causes profound morbidity and identified causes of sickle cell crisis include stress, hypoxemia, dehydration, infection, exposure to temperature extremes. Our patient presented with sickle cell crisis, which we believe was initiated by indoor tanning sessions, after all other potential causes were ruled out. To our knowledge there have been no other reported cases of sickle cell crisis precipitated by indoor tanning. An exact mechanism for this is unknown, but some degree of dehydration, superficial inflammatory response, and intracellular hypoxemia is seen with indoor tanning.
We believe this woman’s case is important to demonstrate indoor tanning as a potential risk factor for sickle cell crisis.In patients with SCD, indoor tanning should be recommended against.
Rajeev Swarup, No Financial Disclosure Information; No Product/Research Disclosure Information