Epidemiological study of fixed drug eruption in Pointe-Noire


  • Conflicts of interest: The author has no conflicts of interest to declare.

N. Ognongo-Ibiaho
Dermatologist and Venereologist, Hôpital Régional des Armées [Regional Hospital of the Armed Forces], Pointe-Noire, Hôpital Régional des Armées Congo
E-mail: onognongoibiaho@yahoo.fr


A prospective study was conducted over a 27 month period in order to determine the epidemiological profile of fixed drug eruption (FDE) observed during a dermatological consultation at Pointe-Noire.
During the study period 54 out of 9,070 persons consulting (0.6%) suffered from clinically diagnosed FDE. The variables studied were: age, sex, medicine and point of sale.
The average age of onset was 30 years.
The frequency of onset was higher in males (38 patients) than in females (16 patients).
The incriminated medicines were: the sulfamides (48 patients) including Cotrimoxazole (45 patients ) and Sulfadoxine and Pyremethamine (3 patients) Coartem® + Doliprane® (1 patient), Chloramphenicol® (1 patient), Amidol® (1 patient), Duocotexin® + Paracetamol® (1 patient), Surquina® (1 patient), Amodiaquine® (1 patient).
The point of sale was illicit (peddlers, markets) for 44 patients; for 10 patients it was a lawful outlet (pharmacies).
This study shows that cotrimoxazole bought at illicit points of sale is the main etiology of FDE in the department, confirming that these medicines are counterfeit. The involvement of dermatologists in the fight against the illicit sale of medicines should be made a priority.


Fixed drug eruption (FDE) is defined as a recurrent skin eruption that leaves behind residual pigmentation. It is pathognomonic of a drug eruption. Poor quality drugs and counterfeits are a global phenomenon. According to WHO:

  • • A counterfeit medical product is a product whose composition and active principles are not in accordance with the rules of science. It is therefore ineffective and above all dangerous for patients.
  • • 60% of counterfeit medical products are found in poorer countries, with 40% found in industrialized countries.
  • • Counterfeiting can affect specialist as well as generic drugs.
  • • Insufficient or non-existent pharmaceutical legislation and poverty favor the illegal sale of counterfeit medical products.

The aim of this study is to determine the epidemiological profile of FDE in Pointe-Noire.

Patients and methods

This is a prospective study carried out over a period of 27 months (from December 2005 to February 2008) in the dermatology department of the Regional Hospital of the Armed Forces in Pointe-Noire, a port city and the economic capital of the Republic of the Congo in Central Africa.

Our work entailed a study of case files on FDE diagnosed clinically. The variables studied were as follows: age, sex, drug, and point of sale.


During the course of the study, 9070 patients attended consultations. Fifty-four patients had consultations concerning FDE, representing 0.6% of total consultations (Table 1).

Table 1.   Distribution of fixed drug eruption (FDE) according to age and sex
Age (years)Males n = 38Females = 16Total

The frequency of cases is distributed as follows: December 2005, three cases; January–December 2006, 17 cases; January–December 2007, 24 cases; January–February 2008, 10 cases. The average age of onset for FDE in Pointe-Noire was 30 years (range 4–67 years).

The frequency of FDE was higher in males (38 patients) than in females (16). Sulfonamides were responsible in 48 patients (89%), and the point of sale (markets or traveling salespersons) was illegal in 42 patients (87.5%) (Table 2).

Table 2.   Distribution of fixed drug eruption (FDE) according to the associated drug
DrugsPlace of supplyFPE n = 54Frequency (%)
Illegal (traveling salespersons, markets)Legal (pharmacies)
Coartem® + Doliprane® 110.18
Chloramphenicol®1 10.18
Amidol®1 10.18
Duo-cotexin® + Paracetamol® 110.18
Surquina® 110.18
Amodiaquine® 110.18

In 45 patients (83.3%), FDE was attributable to sulfamethoxazole and trimethoprim (cotrimoxazole) (Table 3).

Table 3.   Frequency of fixed drug eruption (FDE) according to the sulfonamide
SulfonamidesFPE n = 48Frequency (%)
Sulfamethoxazole and trimethoprim (cotrimoxazole)4583.3
Sulfadoxine and pyrimethamine35.7

The majority of patients (44; 81.5%) bought the drugs from an illegal point of sale (markets, traveling salespersons). Ten patients (18.55%), however, had bought the drugs at a legal point of sale (pharmacies) (Table 4).

Table 4.   Frequency of fixed drug eruption (FDE) according to place of supply
Place of supplyFPE n = 54Frequency (%)
Illegal (traveling salespersons, markets)4481.5
Legal (pharmacies)1018.5


Our study has allowed us to assess the prevalence and instances of FDE at consultations in Pointe-Noire. However, this study was not exhaustive.

Numerous cases might have escaped our notice, either because sufferers are not seeking medical assistance or because they are being treated by healthcare facilities that do not have a dermatologist. The growing global phenomenon of counterfeiting medical products is worrying. Counterfeit medical products constitute a veritable silent epidemic. Studies have shown that 60–80% of Congolese people do not have access to quality drugs due to poverty.1

In our study, antibacterial sulfonamides and illegal points of sale represent the principal etiology of FDE (89%). In tropical regions, the drugs responsible for FDE are cyclines, sulfonamides, Disulone, barbiturates, pyrazoles, and acetylsalicylic acid.2

The illegal place of supply (e.g., traveling salespersons and markets) responsible for the onset of 81.4% cases of FDE confirms the principal characteristics of FDE in countries where the counterfeiting of medical products is rife.


Our study shows that sulfamethoxazole and trimethoprim (cotrimoxazole) purchased from illegal places of supply (e.g., travelling salespersons and markets) is the principal etiology for FDE.

The involvement of dermatologists in information, education, and communication campaigns against the illegal sale of counterfeit medical products is crucial.